Britain’s former finance minister Philip Hammond said he was confident that MPs could block attempts to take the UK out of the European Union without a deal in place on October 31.
He warned of a constitutional crisis if the government sought to push through a no-deal Brexit against the will of parliament, which would at a stroke cut trade and political ties with the 27-nation bloc.
Mr Hammond - who quit his position hours before Boris Johnson became prime minister – has emerged as one of the leaders of the campaign to stop the premier’s “do or die” pledge to leave the EU.
He aimed his fire at unelected officials surrounding Mr Johnson who he claimed were driving strategy that would scupper any potential new deal with the European Union.
Mr Johnson has claimed that he is seeking a deal with the European to allay the fears of business leaders.
But Mr Hammond said calls from the leadership to fundamentally change the deal struck by the EU with Mr Johnson’s predecessor, Theresa May, were “wrecking tactics” aimed at undermining any prospect of a deal.
In his first comments since quitting his job last month, Mr Hammond said that leaving without a deal would “be a betrayal” of what voters believed they were getting after the 2016 referendum.
"Boris Johnson has told me privately, and he's told the country publicly, that he is determined to get a deal, and confident that he can get one,” Mr Hammond told the BBC. “But I fear there are other people around him whose agenda is different."
"A no-deal exit will cause significant harm to the UK economy and, potentially, irreparable damage to the union of the United Kingdom. People need to know the facts."
He said members of Parliament could still prevent Britain leaving the EU without a deal. It puts him at odds with the prime minister’s special adviser Dominic Cummings, who warned MPs this month that it was too late to stop a no-deal Brexit.
House of Commons Speaker John Bercow said he would refuse to let the prime minister suspend Parliament to push through Brexit, The Telegraph reported.
Mr Bercow said he believed that Commons “must have its way” and said he would fight any attempt to circumvent Parliament “with every bone in my body”.
On Tuesday, The Sun reported that Mr Hammond and 20 other senior conservative MPs sent a letter to the prime minister accusing him of having ruined any chance of negotiating a new deal with the EU.
The letter is being touted as evidence of the significant opposition Mr Johnson will face from his own party.
Several other senior MPs, including former cabinet ministers, are believed to have signed the letter.