Former chancellor Philip Hammond has claimed Boris Johnson’s Brexit deal was an agreement previously available to ex-prime minister Theresa May.
The current prime minister presented his “great new” deal to parliament after concluding negotiations with the EU earlier this month.
But Mr Hammond suggested Mr Johnson’s agreement – which came after the EU repeatedly said it would not reopen talks on his predecessor Mrs May’s deal – was only a “limited achievement”.
He told Sky News’ Sophy Ridge On Sunday show: “The deal that Boris has done is a deal that was available to Theresa May 15 months ago.
“A deal that would have split Northern Ireland from the rest of the UK.
“Theresa May rejected that, [and] Boris agreed with her at the time that [it] [was not something any British prime minister could agree.
“He said as recently as 11 September that a Northern Ireland-only backstop would be completely unacceptable to the UK.
“So pivoting to accept something that’s previously been on offer from the EU – it was their preferred solution – and has been rejected because it didn’t work for the UK is an achievement maybe, but a limited achievement.”
After an agreement was reached between Mr Johnson and the EU earlier this month, the bloc’s chief negotiator described the backstop arrangement as “abandoned”.
Mr Johnson has seen MPs give their support – in principle – to his Brexit deal, but then reject his proposed three-day timetable for it to be considered in the House of Commons.
Mr Hammond, who sits as an independent MP after being effectively expelled from the Conservatives by Mr Johnson last month, was among those to back a second reading of the PM’s Withdrawal Agreement Bill but subsequently vote against its timetabling.
The government has now “paused” the passage of the bill through the House of Commons, with the PM only promising more time for MPs to consider the legislation to ratify his deal if they agree to a general election on 12 December.
Mr Hammond urged the government to “stop throwing tantrums” and to offer a longer timetable for MPs to pass the Brexit deal, without pushing for the UK to go to the polls.
Vowing to oppose the PM’s demand for an election in a Commons vote tomorrow, the ex-chancellor said: “This is not the time to be holding a general election.
“It’s a time for cool heads and grown-up government.”
He added: “The key thing now is to get the deal properly scrutinised in parliament.
“That doesn’t mean delaying it by months, it means giving parliament a few days, a couple of weeks, to scrutinise the bill, amend it if necessary, and then we can make progress.
“The government should stop making threats, stop throwing tantrums, and get on with the grown-up business of doing its business.
“Just because it can’t get exactly what it wants, doesn’t mean it should stop working.”
Mr Hammond suggested it is “perfectly feasible” for the UK to leave the EU at the end of November “if the government just stops messing about”.
MPs will be able to try and reshape the PM’s Brexit strategy by tabling amendments to the Withdrawal Agreement Bill.
Mr Hammond revealed he would “probably” oppose efforts to put the Brexit deal to a referendum vote, but could support a bid to compel the prime minister to negotiate a future customs union with the EU.
He also vowed to stand at the next election as an independent candidate, if he does not have the Conservative whip restored by Mr Johnson.
But Mr Hammond, who has now consistently voted against the PM in Brexit votes, promised he would not try to “curry favour” in an attempt to be readmitted to the Tories.
“I am not going to change what I say and what I believe and what I think is important for Britain’s future in any kind of attempt to sneak back in and curry favour with the Conservative leadership,” he said.