In a rare moment of harmony, EU and UK officials seem convinced that the Windsor Framework is the elusive common ground that will resolve the Northern Ireland issue and open up the first post-Brexit era of warm cooperation.

"This is the first agreement I've seen on Northern Ireland since Brexit that I've genuinely believed will work and will stick, or at least has a very strong chance to do that," said one senior figure.

Why is it different this time?

There is a combination of factors. Both sides have been over and over these same issues for the past seven years, so the subject matter is familiar and the passage of time has acted as a balm on some of the harsher politics.

There is also the desire by Brussels and London to get the Northern Ireland Protocol behind them so they can deal with the existential geopolitical issue of our time, the Russian invasion of Ukraine.

Ursula von der Leyen and Rishi Sunak have certainly forged a warm relationship (as have negotiators Maroš Šefčovič and James Cleverly), but there is also self interest. The German president of the European Commission is expected to seek a second term, and the British Prime Minister has desperately needed a diplomatic win in the face of grinding economic problems.

Mr Sunak's arrival opened up fresh space for a more cooperative negotiation. He was less tainted with the Northern Ireland Protocol Bill (NIPB) than either Boris Johnson or Liz Truss.

While Irish officials noted that he was both cautious and meticulous (both welcome ingredients given the rollercoaster of recent years), British officials played down any sense that he was anxious about a trade war with the EU; rather, they said, he was dubious as to how the bill, which would have largely dismantled the protocol, would work.

Rishi Sunak and Ursula von der Leyen presented the Windsor Framework last month

The presentational success of Windsor was down to very careful news management by both sides. In stark contrast to previous landmark agreements, the European Commission was extremely circumspect in its briefings to member states between October and February.

'No major surprises'

Diplomats said they were mainly given generalities, that the mood in the negotiating room was positive, that the teams were working through huge amounts of detail and so on.

London and Brussels knew that if detail leaked out in Brussels it would become a magnet for controversy that could frighten the DUP horses, so most of the selective briefings were done through Downing Street.

"There is nothing where we would have said that this goes too far."

Yet the consistent message from Maroš Šefčovič to national capitals was that the EU would not compromise on the role of the European Court of Justice (ECJ) and that his team was negotiating on the basis of the October 2021 discussion papers - which were updated by further concession papers in June 2022 - offering substantial reductions on checks and controls, but which the UK had said did not go far enough.

However, Mr Šefčovič had made it clear that the EU could go beyond the October and June papers if they were convinced that there were robust safeguards for the single market, that the UK would abide by any agreement (trust was still an issue) and that the Northern Ireland issue could be resolved for the long term.

EU diplomats said that when the deal finally landed in Windsor last Monday, there were no major surprises, although they did want to see the detail.

"This is perfectly within the limits of what we have consistently been told, of what we have been agreeing to," said one source. "There is nothing where we would have said that this goes too far."

So far there have been four exchanges of views between European Commission officials and member state diplomats in what’s called the Working Party UK, and officials say there have been no major concerns raised.

What looked fine on paper when the protocol was agreed with Boris Johnson in 2019 was struggling in real world conditions

"Member states have been using the opportunity to ask questions of the Commission," said one EU diplomat, "aimed at clarifications and understandings, making sure all our national entities and authorities understand what is expected of them if and when this enters into force, particularly when it comes to customs, making sure they understand the full breadth of the political implications of what we're deciding here. But all of that with a positive mindset."

A key narrative appears to have taken root at EU level, a realisation that what looked fine on paper when the protocol was agreed with Boris Johnson in 2019 was struggling in real world conditions in Northern Ireland.

The challenge for Brussels was how to agree to changes in such a way as to avoid London coming back for more concessions a few years later, which was what the pattern suggested.

Mr Šefčovič kept coming back to the notion that practical solutions could be found, but not for Brexiteer demands on sovereignty which were, he said, increasingly ideological.

The EU message on finding solutions was pitched to Northern Ireland businesses, and not the European Research Group (ERG).

However, the view in London was that the EU had taken a significant mental leap.

Since the UK Command Paper in 2021, which aimed for a major revamp of the protocol, the EU has gradually metabolised the notion that since Northern Ireland was not in the single market in a classic way (in that it only covered goods, and certain categories of goods), then a lot more conceptual flexibility was going to be needed.

in January, James Cleverly (L) and Maroš Šefčovič announced a deal on data access

British sources said that Brussels shifted away from orthodox thinking on how a single market model could be grafted onto a contested space like Northern Ireland, given the huge dependence it has on retail goods from a place (Britain) that is outside the single market.

This, they said, started to loosen thinking around customs, agrifood controls, but also VAT, state aid, and in particular the thorny issue of tariff rate quotas (TRQs) on steel.

Facilitating that conceptual breakthrough was data. In January, Mr Šefčovič and Mr Cleverly announced a deal on data access, meaning that EU officials would have access to a blend of UK customs and trade databases covering the movement of goods from Britain to Northern Ireland, tailored to the EU’s risk analysis tools.

"It seemed like a stepping stone along the way, but knowing what we know now, that was the moment where it was clear."

This was a critical safeguard for member states, that it provided a forensic picture of what was entering Northern Ireland so that any suspicious trade flows that might materialise would be identified and checks calibrated accordingly.

"Physical checks will follow a risk-based and intelligence-led approach," said a senior EU official.

However, the data breakthrough was also the moment when both teams decided that, come what may, they would land a deal.

"In hindsight, that was the moment where both sides committed to a solution," said one EU diplomat. "All of us outside of those meeting rooms in the Charlemagne Building [in Brussels] were not as keenly aware of the importance of that announcement. It seemed like a stepping stone along the way, but knowing what we know now, that was the moment where it was clear, okay, we can definitely land this spaceship."

But more work needed to be done. The data access system required data, but who would provide that data and how much would be needed? UK negotiators argued that the smaller and medium sized operators who shipped goods to Northern Ireland were not exporters in the normal sense of the word, and not experts in providing customs detail, including cumbersome commodity codes.

Red lanes and Green lanes

London viewed as another conceptual breakthrough, the agreement that the UK customs agency HMRC would help convert the data that traders could provide into something EU officials could apply their risk analysis tools to.

When taken together with the red and green lanes system (which differentiates goods clearly staying in Northern Ireland from those moving south into the single market), this gave both teams a win.

The EU could be reassured there were sufficient safeguards for the single market, and Mr Sunak could look unionists in the eye and say there is, effectively, no longer an Irish Sea border.

Getting a deal on agrifood checks was just as critical. Ensuring that consumers in the North could buy the same goods as those in the rest of the UK would be vital to popular acceptance of the protocol.

Again, there was give and take.

The UK committing to completing Border Control Posts (BCPs) at Northern Ireland ports reassured Brussels that checks on live animals and food products could be carried out according to EU rules, while the data, labelling and trusted trader systems meant that identity checks on such products would be reduced from 100% to 5% over time.

One UK source said it was an act of "bravery" for the EU to accept this new model, given the sensitivity of food safety to member states.

The Windsor Framework

However, the element of the Windsor Framework which attracted the most scrutiny among member states and in Belfast had been the Stormont Brake.

In a technical briefing for journalists by the European Commission the day the Windsor Framework was published, the Stormont Brake received the most questions and prompted repeated explanations, partly because it had been perceived as somehow being a replacement for (or watering down of) the role of the ECJ.

The DUP has set up a panel to inform its decision on whether to accept the Windsor Framework

Likewise, member states asked the Commission more about the Stormont Brake in meetings of the Working Party UK than any other topic.

In simple terms, the Stormont Brake is an expansion of a provision that is already in the protocol.

The key thrust of the protocol was that EU single market rules for goods would continue to apply in Northern Ireland after Brexit. Those rules are updated and amended all the time through the EU’s secondary legislation known as implementing acts, and under Article 13.3 of the protocol, those amendments and updates would take effect in Northern Ireland automatically.

However, if there was a brand new EU regulation not already in place, then under Article 13.4, the UK could challenge the addition of that regulation to the relevant protocol annexe.

The idea was that the new regulation would only be applied in Northern Ireland by mutual consent, through the EU-UK Joint Committee.

What the Stormont Brake does is that it applies the Article 13.4 mechanism to Article 13.3. In other words, the amending or updating of existing EU regulations or directives could also be challenged by the UK, if 30 MLAs used the Petition of Concern to ask the UK to do so.

"The Stormont Brake enables the UK Government," said a senior EU official, "in certain exceptional circumstances, as a last resort, to say no, we don't want that update of EU law which already applies to apply in Northern Ireland, because the impact of that change … would have such serious consequences for the everyday lives of people in Northern Ireland."

The EU could challenge the notion that that update of EU law does pose such serious consequences, and then the matter would go into the normal arbitration procedure contained in the Brexit Withdrawal Agreement, but the ECJ would not have any role in that arbitration process.

If the EU were successful in arbitration in arguing that the grounds for triggering the Stormont Brake had not been met, or if it had not been triggered in good faith, then the UK could face penalties if the regulation update is not restored in Northern Ireland.

Rishi Sunak visited Northern Ireland in an attempt to sell the Windsor Framework to business groups

However, officials say the whole architecture of the Windsor Framework is designed precisely to avoid such a scenario happening in the first place.

It envisages a lot more stakeholder involvement in the early stages of the EU legislative process, to spot areas where an updated EU law might cause a problem.

This could involve several layers of oversight, including the Specialised Committee, which sits under the Joint Committee, and the Joint Consultative Working Group (JCWG), all bringing EU and UK experts together so they could potentially head off any problem.

While EU officials have played down the significance of the Stormont Brake, the UK sees it as an important victory.

The protocol already has safeguards that deal with the problem of a democratic deficit.

Article 18 provides for the Stormont consent clause, whereby the Northern Ireland Assembly can periodically give its consent to the goods clauses in the protocol to continue.

Article 15 also requires the EU to inform the UK about "planned [EU] acts within the scope of th[e] protocol, including … acts that amend or replace the Union acts listed in the Annexes", and to "ensure that all views expressed by the UK [ ... ] are communicated to the relevant institutions, bodies, offices and agencies of the [European] Union without delay."

Why the Stormont Brake is more appealing to London is that it uses a device within the Good Friday Agreement (GFA) itself, namely the Petition of Concern, which was originally designed to meet the concerns of the minority community in Northern Ireland.

This, officials said, counterbalances the more "monolithic" Stormont consent clause within the protocol, which was designed so as not to give the DUP the ability to pull the protocol down.

Furthermore, UK negotiators were able to get their EU counterparts behind on the Stormont Brake because it would both stabilise Northern Ireland and secure broader support for the protocol.

It has also reassured some member states that the Windsor Framework is using a mechanism which is already there.

The Stormont Brake can only be pulled on specific parts of the EU legislation that mainly deal with customs and goods

According to one EU diplomat, the Stormont Brake needs to be seen in the context of more regular and more structured stakeholder engagement in the process, meaning that there is "even less need" for it.

However, how would the Stormont Brake work in practice and what kind of regulations or directives might cause such "exceptional" difficulties which are "liable to persist"?

The first observation is that the Assembly itself cannot veto the updating of EU regulations.

The 30 MLAs, from at least two parties, who put forward the Petition of Concern can only ask the UK to disapply the regulation, and they will have to have their case made within two months of the regulation taking effect.

Furthermore, the Stormont Brake can only be pulled on specific parts of the EU legislation that mainly deal with customs and goods, and not, for example, equality provisions.

"While the Stormont Brake will apply to most of the EU laws referred to in the protocol," wrote Professor Steve Peers of the University of Essex in a blog post, "it does not apply to all of them; which means that there is no process to object to amending or replacing those EU laws outside the scope of the Brake."

London acknowledged that the bar is relatively high.

The UK’s unilateral declaration on its use warns that MLAs taking this option must "individually and collectively [be] seeking in good faith to fully operate the institutions" and that they must show they are doing so "in the most exceptional circumstances and as a last resort, having used every other available mechanism".

Those mechanisms include having "prior substantive discussion" with both the UK government, the Northern Ireland Executive, businesses and civil society, as well as the EU-UK Joint Consultative Working Group and Specialised Committee structures.

Even after the UK triggers the Stormont Brake it must then discuss the issue with the EU "intensively" within the Joint Committee.

It also seems likely that the Stormont Brake can only be pulled if there is a general problem facing Northern Ireland consumers or businesses, rather than a problem facing one particular community.

That’s because most of the "identity" issues which plagued the original protocol, such as the import of British pies, sausages, seed potatoes, plants etc, had been dealt with by the broad concessions on agrifood and plants within the Windsor Framework.

What comes under the scope of the Stormont Brake?

The potential appears to be where the EU is updating regulation on importing goods from third countries.

One example is the EU’s deforestation law, agreed in December. This law, which amends existing regulation rather than introduces a new regulation, will require companies importing goods into the EU to show due diligence in ensuring that those products have not contributed to deforestation in vulnerable regions.

If the UK does not have similar legislation, then it could mean certain UK products sourced from countries where deforestation is a problem, might not be available in Northern Ireland. It would therefore be a question for the UK as to whether it matched EU legislation in this sphere and thereby argue that the Stormont Brake is not necessary.

Similarly, the EU’s Carbon Border Adjustment Mechanism (CBAM), which aims to restrict imports from around the world if they have been produced using heavy carbon emissions, could impact products entering Northern Ireland from Britain.

Overall, there’s no doubt that uncertainty exists over Northern Ireland diverging from both UK standards in general, and from Irish (EU) standards to the south in particular, if elements of EU regulation are not updated.

"There are instances," said Lisa Claire Whitten, research fellow at Queen's University Belfast (QUB), "where very minor changes to EU acts, because of the unique position of Northern Ireland as the touching point between the two markets of the UK and the EU, could have quite a significant impact in terms of supply chains and access to goods."

Food and drink producers are expected to adopt the EU's higher standards

One prominent example emerged within just days of the Windsor Framework being published.

On Wednesday the European Commission announced it was cutting the amount of arsenic allowed in baby food by 80% due to concerns that it causes cancer.

The impact of the change would mean that Northern Ireland companies making baby food and wanting to export to the south or the rest of the EU would have to abide by the new rules, and would not be able to import ingredients from Britain as part of that process.

Northern Ireland Food and Drink Association Executive Director Michael Bell told the Financial Times that members were likely to adopt the EU’s higher standards.

"We are trying to maintain the ability to trade both to Europe and Britain which was possible before Brexit," he said.

There are many unanswered questions, such as what will happen to a Petition of Concern if it is applied ahead of the Assembly collapsing.

Does the Stormont Brake collapse with the institutions, or does it survive and then still apply? It is not clear if the EU and UK are agreed on this.

There are many pitfalls ahead as the highly complex new regime takes root. Both the UK and EU will play up the best of both worlds narrative, but there is much which remains untested.

The important point, from the EU and UK’s perspective, is that both sides appear to be on the same page when it comes to flexibility, facilitations and pragmatism.

To the EU, there are plenty of safeguards and unilateral declarations from the UK that will ensure the process is not in crisis within a few months.

What appears to matter now, more than before, is that the Protocol is implementable.

EU member states are expected to endorse the changes on 21 March, mandating Mr Šefčovič to agree them with Mr Cleverly through the EU-UK Joint Committee.

The EU will then press ahead with changes to its own legislation, and the UK is expected to do the same.

"The intention would be for the UK to make its formal decision in parallel with the EU on that same day as the General Affairs Council [21 March]," said an EU diplomat. "So that no one is taking the first step and then waiting for the other, but rather they are doing this in tandem. This is an important signal of mutual trust and mutual cooperation."