The EU has raised with UK ministers claims by some Tory MPs that they will not support the current Brexit deal even if Boris Johnson's demands to scrap the backstop are met.
Mr Johnson, the new British prime minister, has said the backstop, the insurance policy to avoid a hard border, must be abolished if there is to be an orderly Brexit at the end of October.
The EU is adamant that the current withdrawal agreement, which contains the backstop, will not be reopened or renegotiated.
Stephen Barclay, the UK Brexit secretary, laid out Mr Johnson's position in a phone call with EU agriculture commissioner Phil Hogan earlier this week.
However, Mr Hogan indicated to Mr Barclay that the EU is aware that members of the so-called European Research Group of hard-Brexit Tory MPs have already said the abolition of the backstop is not enough.
Mr Hogan repeated that the backstop would not be changed and challenged Mr Barclay to come up with some ideas to break the current impasse.
After the phone call, Mr Barclay said: “We’re leaving the EU on October 31st with or without a deal.” He added that he stressed to Mr Hogan that “while we’re ready to energetically enter into new negotiations in a spirit of friendship, the backstop must go”.
Political declaration
The EU and the Government have categorically ruled out any changes to the backstop and the wider withdrawal agreement, but they have said that the political declaration, the looser document which aims to sketch out the post-Brexit relationship between the UK and EU, can be amended.
Recent weeks, however, have seen members of the ERG say they want the withdrawal agreement in its entirety scrapped. One MP, Mark Francois, said: "If there were any attempt to revive the withdrawal agreement, even without the backstop, the ERG would vote against it."
Mr Hogan is understood to have brought up such claims in his phone call with Mr Barclay.
“The UK had made an agreement with the EU in good faith and it is up to them to propose ideas to break the impasse, taking account of the expressed view of the ERG members that the removal of the backstop would not convince them to vote in favour of the WA under any circumstances,” one source said, adding the EU is ready for new ideas “under the future relationship”.
‘Good faith’
A spokesman for Mr Hogan said the phone call with Mr Barclay was a follow-up to a previous meeting between the pair. The spokesman said Mr Barclay “confirmed the UK government’s commitment to securing a deal with the EU and to the Good Friday [Belfast] Agreement, while also recalling that the withdrawal agreement had been rejected repeatedly by the House of Commons.
“In response, commissioner Hogan reiterated the EU’s well-established position that the withdrawal agreement, which was negotiated in good faith between the EU and the UK, is not open for renegotiation.
“If the UK government continues to reject the withdrawal agreement, it is now the responsibility of the UK government to come forward with proposals for the future EU-UK relationship. The UK government can be assured that any such proposals will be given appropriate consideration by the EU.”
Mr Hogan has been nominated for another five-year term at the European Commission by Taoiseach Leo Varadkar but he is not expected to find out what portfolio he will be given in the new commission until September.