The European Parliament has voted to ratify the EU's post-Brexit trade deal with Britain, but not without issuing bitter final warnings that trouble lies ahead in cross-Channel ties.

The official result of the vote was not to be published until tomorrow morning, but the decision was not in doubt.

"Today the European Parliament voted on the most far reaching agreement the EU has ever reached with a third country," the president of the assembly, David Sassoli, said.

"This can form the foundation on which we build a new forward-looking EU-UK relationship," he said, warning that MEPs would monitor the implementation of the deal and "not accept any backsliding from the UK government".

"You cannot have the advantages of EU membership while being on the outside. However, this agreement goes a long way to mitigate its worst consequences."

The vote ratifies the bare bones trade deal that was sealed on Christmas Eve after nine months of bad-tempered negotiations.

This will provide the framework for Britain's new relationship with the 27-member union, five years after British voters shocked the world by voting to end its 47-year membership.

But the EU parliament vote comes amid multiple feuds over the UK's implementation of Brexit agreements and angry finger-pointing about the supply of the Covid-19 vaccine from AstraZeneca.

"We know it will not always be easy and there is a lot of vigilance, diligence and hard work ahead of us," EU chief Ursula von der Leyen told a session of parliament ahead of the vote.

"But while today's vote is obviously an end, it is also the beginning of a new chapter," she said.

Britain left the EU on 30 January 2020, but its new life with Europe only really began after a transition period ended on 31 December, when London was no longer bound by the bloc's laws and rules.

Officially called a trade and cooperation agreement (TCA), the deal creates a new relationship that provides for zero tariffs and zero quotas on goods traded between the EU and UK.

But it is less ambitious than many Europeans had hoped for, with nothing on foreign policy and defence nor any commitment to close alignment on environment, health and other regulations.

More harmonised rules would have removed the requirement for some customs checks and paperwork on goods moving between the EU and UK, which has made business more burdensome and stirred unrest in Northern Ireland.

Cross-Channel trade volumes have plummeted, with EU imports from the UK down by nearly 50% and exports into Britain down 20% in the first two months of the deal's application.

The deal also makes no provision for financial services, threatening the City of London's preeminence as the European hub for capital markets, banking and investment.

MEPs had demanded extra time to vet the pact, which also includes a painfully won deal on fishing that saw EU boat crews lose much of their access to bountiful UK waters.

The European Parliament further delayed its vote in part to protest unilateral delays by London in implementing customs checks in Northern Ireland, one of the most contentious issues in the divorce.

Brussels has launched legal action against London over the Northern Ireland protocol, while a row over the supply of UK-based AstraZeneca's coronavirus jab has also embittered cross-Channel relations.

But, despite the acrimony, the European Commission, which handles ties with the UK for the Europeans, urged MEPs to approve the pact, arguing that it will better help keep Britain in line.

The UK, meanwhile, had made it clear that it would not approve any further delays, despite the risk of the whole deal being annulled if the MEPs did not vote by 30 April.

Solutions can be found to outstanding NI trade issues - Coveney

The Minister for Foreign Affairs has said that solutions can be found to the outstanding issues around trade in Northern Ireland post-Brexit.

Simon Coveney said finding a way forward within the framework of the Northern Ireland Protocol will foster stability in Northern Ireland when it is "needed now more than ever".

"The protocol is the only solution to the problems created by Brexit for the island of Ireland and we firmly support ongoing contacts between EU and UK on its implementation," Mr Coveney told an Irish parliamentary committee.

He said the Government had listened to the concerns voiced about some aspects of how the protocol operates.

"The EU is doing everything it possibly can to reflect these concerns and working with the UK to implement the protocol in a way that impacts as little as possible on people's everyday lives and on trade," he added.

"I firmly believe that acting together within the framework of the protocol, the EU and UK can find solutions to the outstanding issues.

"Finding a sustainable and collaborative way forward is ultimately to the benefit of all communities in Northern Ireland and to the EU and UK as a whole.

"It will also foster stability that given recent very concerning disturbances in Northern Ireland is needed now more than ever."

Additional reporting PA