The Irish question is back and is once again plaguing the relationship between Britain and Europe.

This time the enmity revolves around a physical EU presence in Belfast. The European Commission insists that the Irish Protocol requires officials to oversee checks and controls on goods going from Britain to Northern Ireland, and that they need an office to work out of. 

The UK says the Protocol does not legally require this and such an office would be divisive and contrary to the aims of the Good Friday Agreement.

Some observers now believe the issue has got out of control because of a lack of trust. With British Prime Minister Boris Johnson and other senior UK figures having boasted there would be no checks or controls between Britain and Northern Ireland, the European Commission does not trust the UK to meet its obligations.

"The Commission could have people based in Dundalk who could drive to Belfast every day and look over the shoulders of the UK authorities [carrying out checks]," says one source close to the discussions. "They can achieve their functional requirement. But the Commission wouldn't have had to be so pushy if they could  trust the UK to do the right thing."

However, RTÉ News has established that back in February 2019 the idea of an EU office in Belfast was regarded enthusiastically by the UK in an exchange of letters with the EU.

It turns out that the Foreign Office Permanent Secretary, Simon McDonald, wrote to his EU counterpart that the UK wanted to keep EU embassies, not only in Belfast, but in Edinburgh and Cardiff as well.

The same Mr McDonald was instrumental in flatly turning the EU down on this occasion, a little over a year since he first embraced the idea.

How did things come to this?

British and EU officials have an entirely different recollection of how the issue evolved. 

Back in October 2018, after Theresa May’s Withdrawal Agreement was concluded, it seemed clear the European Commission’s offices in Cardiff and Edinburgh were going to close, and the EU representation in London would be replaced by a lower status EU delegation.

As part of this reconfiguration Martin Selmayr, the then Secretary General of the Commission, suggested that the EU should keep its presence in Belfast, due to the existence of the backstop.

According to Brussels sources, the issue moved slowly and there were no major objections from the UK side.

Then May’s Withdrawal Agreement foundered on the rocks of repeated rejections by the House of Commons. She was forced to resign, Boris Johnson was elected leader, and in the autumn of 2019 negotiated a revised Protocol.

The issue of an EU presence in Belfast was still in the mix, according to Brussels sources. Earlier that year the issue had been passed to the EU’s External Action Service (EEAS), which handles all the EU’s overseas delegations.

The EEAS had doubts about a Belfast office being a fully-fledged European Commission delegation, such as those located in capitals around the world. 

The conversation then moved to the office simply having a technical function that would reflect the work required by the Protocol Johnson had just negotiated.

It did not appear a controversial issue at EU level. This would be an office where the EU could make sure that the Protocol, which is designed to avoid a hard border on the island of Ireland and to protect the EU’s single market, was being properly implemented.

"For most member states, they couldn’t give a toss," says one EU diplomat.  "They just want an office where the Commission can come back and say, it’s being implemented properly."

British officials take an entirely different view. They see the issue as harking back to the first Commission backstop text in February 2018, which envisaged joint checks and controls by UK and EU officials.

The idea of joint EU-UK controls was seen as an unacceptable infringement of UK sovereignty by London. As such, when Theresa May’s Protocol was concluded, it provided for UK customs officials to do the checks, but with EU officials periodically overseeing such checks.

When Boris Johnson renegotiated the Protocol, his government toyed with the idea of binning that approach altogether and having no EU presence at all. In the end, however, that idea was dropped.

According to London, the first time the idea of an EU presence in Belfast came up was in a letter from Helga Schmid, the Secretary-General of the EEAS, on 12 February of this year.

British sources say this came like a bolt from the blue, at a time when the British and Irish governments had just managed to restore the Northern Ireland Assembly.

Schmid argued that Article 12 of the Protocol, which requires EU officials to "be present during any activities of [UK] authorities" when carrying out EU customs and regulatory checks, meant the EU should have a permanent presence in Northern Ireland.

The EU would need "very particular capabilities and competences on the ground, distinctive from the more traditional competences of any other EU delegation."

The EU hoped the office would be up and running by the summer of 2020, in time for the transition period to end and the new system to take effect on 1 January.

McDonald sent a somewhat terse reply that an office would not be appropriate.

Schmid sent a stronger follow up letter on 25 March. Article 12 of the Protocol gave the EU certain rights.

"It is necessarily within the discretion of the EU to determine the extent to which it wishes to exercise these rights," she said.

She added: "At least during the initial phase of the application of the Protocol, the EU will want to avail of these rights on an ongoing basis. To do so effectively, an office in Belfast staffed by technical experts is indispensable."

Furthermore, the UK was obliged to facilitate EU officials "to ensure the EU is in a position to exercise its rights effectively." [My emphasis]

The second letter did not prompt a rethink by the UK. On Monday Schmid received a second rejection from Penny Mordaunt MP, a minister of state and paymaster general.

Mordaunt stated that Article 12 did not require an EU delegation office, "or indeed any other permanent EU presence in Northern Ireland."

Furthermore, since the two main unionist parties had declined to sign a joint letter by the leaders of Sinn Féin, the SDLP, the Alliance Party and the Green Party supporting the office, it meant the idea had "attracted controversy, [which] would in our view be divisive in political and community terms."

This was three days before the first meeting of the Specialised Committee, which brings EU and UK officials together to implement the Protocol. 

While the video conference was deemed by both sides as constructive - indeed more constructive than expected - the strongest exchanges were over the EU office issue.

"The EU side had a fairly sharp response," says one source briefed on the video conference, "regretting very strongly the British approach, underlining the importance of this office in implementing the Protocol."

The UK side responded equally sharply.  One official said implementing the Protocol was hard enough without "needlessly" introducing the idea of an EU office in Belfast into the mix, a request which had split the North’s political parties along entirely predictable community lines. 

The video conference was joined by officials from France, Germany, Spain, Greece, Belgium, the Netherlands and Ireland, and by a senior official from the Northern Ireland Executive.

The Irish official said the Government here saw the office as "logical" given the demands of Article 12 and that it in no way undermined the Good Friday Agreement, "not least given ongoing EU support for the peace process."

The official said Ireland hoped that "such a presence could be accommodated in a way that satisfied both sides’ needs and sensitivities."

Although they see the roots of the stand off differently, all sides say they are dismayed that the issue has escalated so quickly, especially when there is already such a deep level of mistrust over the implementation of the Protocol. 

Brussels sources suggest that any objections raised by London from the moment Boris Johnson signed the revised Protocol back in October last year related not to unionist concerns, but to the fact that if Belfast had an EU office then Scotland would want one as well.

Helga Schmid’s letter on February 12 suggests she was trying to reassure the UK that Belfast was a special case and that there was no reason for Scotland to have a similar EU presence. 

"The situation regarding Ireland and Northern Ireland is unique compared to that of the other devolved nations of the United Kingdom, and thus merits a specific solution," she wrote to Sir Simon McDonald.

"As the situation regarding Scotland and Wales is fundamentally different compared to Northern Ireland, we do not foresee any EU presences in Edinburgh or Cardiff."

However, it turns out there was an earlier exchange of letters between Schmid and McDonald on the issue.  This time it was back in February 2019.

In the context of UK protestations that the request for an EU presence in Belfast was a bolt from the blue, the February 2019 correspondence provides a remarkable twist.

Schmid had written to McDonald back then saying that the EU wanted to keep an office in Belfast because of the Protocol, which at that stage was still the Irish backstop, and because of continued EU PEACE funding for Northern Ireland.

Contrary to his flat refusal this year, McDonald not only agreed with the idea, but had seemed enthusiastic.  Nor was the  enthusiasm confined to the idea of an EU presence in Belfast.

According to an extract of his letter sent on 11 February 2019, McDonald wrote: "The UK government supports the continued presence of EU offices in Edinburgh and Cardiff, alongside London and Belfast, given the longstanding relationship the EU has with all devolved nations…"

Granted, this was an aspiration under Theresa May’s administration, and the approach under Boris Johnson is very different.

However, this puts a large question mark on UK claims that the request by Helga Schmid in February of this year was the first they’d heard of an EU presence in Belfast.

An EU official told RTÉ News: "The UK cannot have been taken by surprise by this. The possibility of opening an office in Belfast has been discussed for a long time at this stage.  The EU has been consistent on this point."

Why did the EU not insist on having the office requirement spelled out in Article 12 when the Protocol was renegotiated last year?

According to a number of sources, the EU wanted the Protocol to remain as untouched as possible, and that any changes to the text would be a UK "ask", and not an EU one.

In other words, the Commission believed that if Brussels itself reopened the text on Ireland, then other member states - most likely Spain, and its position on Gibraltar - would want another part of the Withdrawal Agreement opened as well.

So Brussels believed it best to leave any such demands to the UK. "There was nothing that was renegotiated that was not at the UK’s request or as a direct consequence thereof," says a source familiar with the negotiations.

This is flatly rejected by British sources who say the reason the EU didn’t ask for an EU office to be inserted into Article 12 is because London would have rejected it right away.

That may have been true under the more hardline Boris Johnson, but it would not have been true under Theresa May, as evidenced by the February 2019 correspondence between London and Brussels.

The UK is shortly expected to table ideas on what it believes is a more appropriate arrangement for EU technical experts operating under the Protocol. It’s understood London will propose an ad-hoc arrangement where officials fly in for a number of days and fly out again, staying in hotels.

One source suggests that the UK, and all other member states, would routinely be subject to audits of Common Agriculture Policy spending by EU audit officials who would fly in, carry out inspections for a number of days, and fly out again.

Monitoring how British customs, VAT and veterinary officials are carrying out checks and controls under the Protocol should be doable under the same model, sources say.

However, the EU says there is no comparison between annual audits for a policy which has been in place for years, and with which the UK as a member was legally aligned, and what is required in the Irish Protocol.

"We’re taking an entire region of the UK," says a senior EU source, "and we’re basically trying to apply a dual system to it, where it’s de facto in the EU’s common customs territory, and it’s legally part of the UK customs territory. And you’re going to have dual VAT systems and so on. It’s never been done before, anywhere."

The issue is either dead or very much alive, depending on which side you speak to. 

"It’s definitely not closed," says one EU source, "and both sides are remaining engaged on the issue. I don’t think the EU is going to let it go."

London is of the view that the matter is closed, although if a third letter is sent by the EU there would, of course, be a response.

But the EU is taking this seriously. 

On Thursday night the European Commission circulated a nine-page note to member states spelling out in detail what the UK has to do in order to be compliant with the Protocol.

The note said the Protocol was the "biggest challenge" when it came to putting into effect the Withdrawal Agreement, given its "technical complexity and political sensitivity."

Essentially a whole new regime would be taking effect on 1 January 2021 (unless, of course, the UK decides to extend the transition period) and the most dramatic changes needed "timely and thorough preparation" and required "the most extensive adaptations by businesses."

The first priorities were customs procedures, sanitary and phytosanitary (SPS) controls, a dual VAT system, based on EU rules for goods and UK rules for services, new rules for fishing fleets which land fish directly in the North, and other technical preparations. 

Setting up IT systems and databases for customs, VAT and excise would already have to be under way by 1 June - just four weeks time.

As such, the note emphasised, "discussions on the [European] Union presence in Northern Ireland need to be advanced as a matter of urgency as well. We need clarity on the administrative arrangements before we can recruit staff, organise the uptake of their functions, etc."

It is hard to see how this can be resolved amicably. By so readily jumping on the notion that the EU request had caused "controversy" and was "divisive", the UK has given unionists ample cover to vociferously reject the idea of an EU office in Belfast. 

So the EU presence in Northern Ireland has become not just a proxy for the issue of trust, but a symbol that will antagonise both the nationalis/unionist, remain/leave fault lines. 

History reminds us that in Northern Ireland, symbols are the last things to get fixed.