THE President of the European Commission has told Boris Johnson directly that she will not rewrite the post-Brexit trade deal for Northern Ireland.

In a half hour call, Ursula von der Leyen told the Prime Minister that Brussels would be “flexible and creative” over the Northern Ireland protocol, “but we will not renegotiate”.

The rebuff, less than 24 hours after the UK demanded “significant change” to the deal, raises the chances of the UK unilaterally suspending parts of it.

On Wednesday, Brexit minister Lord Frost demanded the terms of the protocol, which he negotiated, be overhauled, saying “we cannot go on as we are”.

Mr Johnson also said the EU’s approach had been “inflexible” and there was a “huge opportunity to find reasonable, practical solutions to the difficulties” in Northern Ireland. 

The PM urged German Chancellor Angela Merkel to spur the EU “collectively to engage in a constructive and detailed discussion on the UK’s proposals”.

However Ms von der Leyen shot down the idea after Mr Johnson called her to present the proposals on Thursday morning.

She tweeted afterwards: “The EU will continue to be creative and flexible within the Protocol framework. But we will not renegotiate.

“We must jointly ensure stability and predictability in Northern Ireland.”

The protocol was put in place to ensure there would be no hard border with Ireland, but effectively put a trade barrier down the Irish Sea instead. 

Despite Mr Johnson’s promising there would be no customs checks, the arrangement has created significant checks on goods moving from Great Britain to Northern Ireland, with far more due to kick in from October when the current ‘grace period’ ends.

The arrangements have already meant fewer supermarket product lines, with Marks & Spencer this week confirming some “gaps on shelves” this Christmas.

One UK proposal is a so-called ‘honesty box’ in which UK traders declare goods sent from GB to Northern Ireland will stay there, and not be sent on into Ireland and hence the EU.

With Unionist politicians in Ulster demanding the protocol be scrapped as it undermines the UK, Lord Frost told peers that the economic and social damage would have justified invoking Article 16, effectively tearing up parts of the deal.

Downing Street said Mr Johnson “set out that the way the protocol was currently operating was unsustainable” during the call with Ms von der Leyen, and that “solutions could not be found through the existing mechanisms of the protocol”.

A spokesman said: “We had set out proposals for significant changes to it. He [the PM] urged the EU to look at those proposals seriously and work with the UK on them.”

Later, Mr Johnson called Ms Merkel to warn the protocol was “failing to deliver” on objectives to minimise disruption and preserve the peace agreement.

“The Prime Minister underlined that solutions could not be found through the existing mechanisms of the protocol and that was why we had set out proposals for significant changes to it,” a statement said.

“He urged the Chancellor and the EU collectively to engage in a constructive and detailed discussion on the UK’s proposals.”

Earlier in the day, Business Secretary Kwasi Kwarteng said the protocol, which effectively keeps Northern Ireland in the EU’s single market for goods, was only temporary.

“A deal is a deal but it wasn’t something that was going to last forever,” he told Sky News.

“Nobody thought the Northern Ireland Protocol was going to define the role of Northern Ireland within the UK forevermore, it was something that was flexible.

“When people say they’re not going to look at the protocol again, I say ‘well, let’s just see’.”

SNP Constitution Secretary Angus Robertson has said the situation is entirely down to the UK Government’s “pursuit of a damaging hard Brexit”.