Boris Johnson set for row with Tory Brexiteers after admitting backstop is only part of current deal he is seeking to change

Boris Johnson is on course for a major row with Conservative Brexiteers after Downing Street admitted that he is only seeking changes to one part of the current Brexit deal.

No10 said the prime minister was only asking the EU to remove the controversial Northern Ireland backstop, which would keep the UK in a customs union with the EU if no other way is found to keep the Northern Ireland border open after Brexit.

In recent days Tory Eurosceptics have demanded that other parts of the withdrawal agreement also be amended, including the proposed £39bn divorce bill and the length of the transition period.

Mr Johnson has said that the current deal, negotiated by Theresa May, is ”dead”, but the admission that he is happy with the vast majority of the 585-page agreement will infuriate Brexiteers.

Asked whether the prime minister supported the current deal if the backstop was removed, a Downing Street spokesperson said: “We have been clear that the changes we are seeking relate to the backstop.”

She added: “The PM has had good discussions with EU leaders both last week in France and Germany and at the weekend [at the G7 summit in Biarritz]. There is a clear understanding now that the commitment to leave on 31 October is absolute and that the PM wants to do so with a deal.

“He’s also been setting out very clearly the reasons why the backstop is unacceptable to us and I think what is clear is that if there is goodwill on both sides and a determination to get things done, solutions to the backstop exist. The PM believes they should be discussed without delay.”

The comments come days after senior Eurosceptics warned Mr Johnson that he must demand further amendments to the deal.

David Davis, the former Brexit secretary, suggested last week that removing the backstop would not be enough to persuade him to vote for the deal again.

He told The Daily Telegraph: “I’d argue for contingency on the money. I’d argue for tighter limits, timetable limits, sunset clauses on ECJ and things like that.

“I’d have a small shopping list. It wouldn’t be a ridiculous one, but one I think that any serious European parliament and any European Council that wants a deal could go with.

“If I were doing this for Boris, I would be insistent that they make the bill – the £39bn, the second half of it – contingent on progress on the future economic partnership.”

And Sir Bill Cash, another prominent Tory Eurosceptic, said: “You can’t restore self-government as a cut and paste operation and I am sure they understand that – taking parts of the withdrawal agreement.

“We will be governed for a number of years by the other 27 member states under the existing draft withdrawal agreement ... even with the backstop removed.”

Mr Johnson’s Brexit negotiator, David Frost, will travel to Brussels for further talks on Wednesday.

Reports suggest that the government is drawing up a plan that would see the UK agree to abide by EU regulations on some products, including agricultural goods, in order to avoid the need for checks at the Northern Irish border.