Michel Barnier has said there is “no way” the European Union should consider renegotiating the Northern Ireland Protocol.
The EU’s former chief Brexit negotiator said there was “room” to work on operational solutions related to concerns over the implementation of the protocol, but said the bloc should not accept a renegotiation.
Mr Barnier also said the British Government had made a “mistake” in its negotiating strategy with the EU by attempting to divide the member states.
“The protocol is not the problem, it’s the solution to the problems created by Brexit,” Mr Barnier told RTE’s Prime Time.
“There is a room for working on pragmatic and operational solutions to address some concerns of the Brits.
“But there is no way, in my view, to accept any renegotiation of this protocol.”
The protocol was agreed by the UK and EU as a way to maintain a free-flowing land border on the island of Ireland after Brexit.
The leaders of Northern Ireland’s four main unionist parties signed a joint declaration in opposition to the protocol on Tuesday.
The declaration is signed by DUP leader Sir Jeffrey Donaldson, UUP leader Doug Beattie, TUV leader Jim Allister and PUP leader Billy Hutchinson.
In response, Irish premier Micheal Martin said: “The government is remaining focused, calm and flexible, in solution-mode around the protocol and around the relationship between the European Union, and the United Kingdom.”
Unionists in Northern Ireland have been vehemently opposed to the terms of the Northern Ireland Protocol, which sees additional checks on goods arriving into the region from the rest of the UK.
Mr Barnier said the EU must be “clear and firm” with the UK on the issue, but said there is “some margin” to address concerns over how it operates.
Mr Barnier, responding to questions in his recent book My Secret Brexit Diary, also said the British had made mistakes in their approach to negotiations.
He said: “I think that the Brits made a mistake in their strategy, because they tried to divide us, or bypass my team to engage directly with the member states. It was a mistake.
“I was the negotiator that had been the negotiator of the commission, the member states and the (European) Parliament, and they didn’t understand this triple mandate I received.
“Number two, we were bound on the European side by unanimity.”
He admitted that one of the options on the table to resolve the issue of the Irish border was for Ireland to be excluded from the EU’s single market.
However, Mr Barnier said he personally considered this option “impossible”.
He said he had told the then-Irish premier Leo Varadkar in February 2019 that checks to protect the single market “must be implemented somewhere, whether around the island or within it”.
He added: “For me, it’s impossible to exclude one member state because of the Brexit from the single market.
“The single market is our common asset, including Ireland. It’s the reason why we tried during three years enough to find a solution with the Brits and finally we found the solution with the Brits.”
Mr Barnier said solutions had been found first with Theresa May, and then again with Boris Johnson – and insisted the Prime Minister knew exactly what he had signed up to.
He said: “With Boris Johnson. Not without him, or against him. With him, with his team, a professional team.
“And Boris Johnson knows exactly what he signed.”
He also revealed there were concerns in the EU that other member states could follow the UK out of the bloc.
“There is always a risk but we have to understand the reasons,” he said.
“Very British reasons, social anger, popular feeling, which is quite different from populism. We have to understand, to listen and to answer.
“I think the EU begin to answer by some change in some policy. External policy, trade policy, industrial policy, the policy of migration also.
“We have to continue to intensify change.
“Because Brexit was unlikely even for Farage and some others, but it happened. So we have to be very careful.”