The EU has shelved plans to approve Boris Johnson’s Brexit deal after Brussels accused the UK of violating the agreement.
The trade deal between the UK and EU has been in provisional force for two months but needs to pass a vote in the European parliament to become permanent.
Leaders of the legislature’s political groups intended to agree a date for the final vote at a meeting on Thursday, but instead agreed to hold off after the latest move by the UK.
On Wednesday, Boris Johnson’s government said it would unilaterally change parts of the agreement to better suit UK businesses in Northern Ireland.
“The conference of presidents this morning decided not to agree a date to ratify the TCA [Trade and Cooperation Agreement], pending developments yesterday," one EU source told The Independent.
“The European parliament leaders want to see where this is going.”
Watch: Brexit - European Parliament declines to fix date of EU-UK trade deal vote amid new row over Northern Ireland Protocol
Following the meeting, senior German socialist MEP Bernd Lange tweeted: “Still valid: ‘Should the UK authorities breach – or threaten to breach – the withdrawal agreement, through the United Kingdom Internal Market Bill... or in any other way, the European parliament will, under no circumstances, ratify any agreement between the EU and the UK’”.
Boris Johnson’s official spokesperson said he was not aware of the Conference of Presidents’ decision, but added: “We want the EU to ratify the TCA as soon as possible.
“We have made clear we will allow for extension to the end of April, but we expect the EU to ratify the deal by that deadline.”
The European Commission, the bloc's executive, on Wednesday evening pledged legal action after UK ministers said they would extend a ‘grace period’ designed to allow UK supermarkets and suppliers time to adapt to new trade barriers across the Irish Sea.
Maros Sefcovic, vice president of the commission, said that would be a “violation” of the protocol agreed with the UK.
He also warned it would be the “second time that the UK government is set to breach international law”, following a similar row last year.
In a statement the commission said Mr Sefcovic would inform Lord Frost, the minister who helped negotiate the Brexit deal, that it would “respond to these developments in accordance with the legal means established by the withdrawal agreement and the Trade and Cooperation Agreement.”
It added that the EU had “strong concerns over the UK’s unilateral action, as this amounts to a violation of the relevant substantive provisions of the protocol on Ireland/Northern Ireland and the good faith obligation under the withdrawal agreement.”
“This is the second time that the UK government is set to breach international law.
“This also constitutes a clear departure from the constructive approach that has prevailed up until now, thereby undermining … the mutual trust necessary for solution-oriented cooperation.”
The grace period – a temporary relaxation of checks – had been due to expire at the end of this month.
At that point supermarkets in Northern Ireland, which have struggled with supply problems since the government’s Brexit deal came into force on 1 January, had expected to see their woes worsen.
It’s the British government essentially breaking the protocol – breaking their own commitments againSimon Coveney, Irish foreign minister
But Northern Ireland secretary Brandon Lewis said the government would be “taking several temporary operational steps to avoid disruptive cliff-edges as engagement with the EU continues through the Joint Committee”.
Controversially he announced the new grace period would continue until at least 1 October.
Ministers had asked the EU to extend the grace period until 2023, but Brussels had declined to do so so far.
Watch: 10 ways to Brexit proof your finances
Mr Johnson’s spokesperson insisted that UK officials had notified the European Commission and the Irish Government of their move earlier this week, though he was unable to give a precise date or time.
“We need to make progress to address the disproportionate impact some of the aspects of the protocol are having on the citizens of Northern Ireland, contrary to their intended purpose,” said the spokesman.
“That’s why following official-level notification to the Commission earlier this week, we have set out the temporary technical steps, which largely continue measures already in place, to provide more time for supermarkets and parcel operators to adapt and to implement the new requirements in the protocol.
“These are sensible and necessary practical steps to address some of the issues being faced. We continue to want to work through the Joint Committee to address the issues raised in Mr Gove’s letter of a few weeks back.”
Irish foreign minister Simon Coveney said on Thursday that the latest episode showed the UK was a negotiating partner the EU “simply can’t trust”, adding: "It’s the British government essentially breaking the protocol – breaking their own commitments again." Mr Johnson's spokesperson rejected the characterisation.
Louise Haigh, Labour’s shadow secretary of state for Northern Ireland, urged Boris Johnson take "personal responsibility for finding lasting solutions that lower tension and make the protocol work".
"Unilaterally undermining his own agreement has only provoked further instability," she said.
“He should show leadership and hold urgent talks with all parties to the protocol, and Northern Ireland’s political parties, to ensure the voice of all communities is being heard loud and clear.
“The Belfast/Good Friday Agreement is the basis on which communities have lived in peace for two decades. It has endured because cooperation is the only way – that must be the focus.”