Prominent members of Theresa May’s cabinet are rising to block prime minister Boris Johnson from delivering a no-deal Brexit.

Former Chancellor Philip Hammond warned on Tuesday that Westminster will block a no-deal Brexit if Johnson tried to wrench Britain out of the European Union on October 31 without an agreement. Johnson has vowed to leave the bloc in 77 days if the EU does not agree to a new deal that would not entail the Irish backstop.

Mr Hammond told the BBC on Tuesday that parliament is “clearly opposed” to a no-deal exit, calling on Johnson to respect that. In a letter to the Times of London, Hammond said that no-deal would in fact be “a betrayal” of the 2016 referendum.

The House of Commons speaker John Bercow told an audience in Edinburgh Festival that MPs could prevent a no-deal Brexit and that he would fight any attempt to suspend parliament in order to force a no-deal Brexit “with every bone in my body.” In an open challenge to the former Leave Campaign Manager Tom Barton, Hammond told BBC 4 Radio that “the unelected people who pull the strings of this government” are asking the EU for impossible concessions that are leading to no-deal.

Hammond’s views were echoed by Amber Rudd, the Work and Pension Secretary that Boris Johnson kept from Theresa May’s cabinet. Rudd urged Johnson not to attempt to force through a suspension of parliament, warning that she remains “a great admirer of parliament and of parliamentary sovereignty,” concluding that she expects to work with Westminster rather than against it.

There are in total seven former conservative cabinet ministers who signed a letter warning Johnson not to suspend the parliament, including David Lidington, David Gauke, Rory Stewart and Greg Clark, all of whom resigned before Mr Johnson took office.

Responding to the combined offensive, Johnson admitted on Wednesday that there is indeed an increased likelihood of the UK being “forced to leave with a no-deal” in October. Speaking during a Facebook event hosted at Downing Street, Johnson spoke of “a terrible kind of collaboration” between “people who think they can block Brexit in Parliament and our European friends.”

Furthermore, No 10 accused Hammond of undermining the UK’s negotiating stance by blocking funds required to prepare for no-deal while he was in office. The former chancellor took to Twitter to reply, recalling that he voted three times in favour of the Withdrawal Agreement negotiated by Theresa May and cannot be accused of undermining Brexit.

Labour leader Jeremy Corbyn called on Tory rebels on Wednesday to agree to a caretaking government led by himself that would postpone the UK’s departure, call snap elections, and campaign for a second referendum in which Remain would be an option.

Mr Corbyn outlined his plan in a letter addressing all opposition leaders, which Liberal Democrats were swift to reject, as they do not find the Labour leader credible. Green MP Caroline Lucas welcomed Mr Corbyn’s call for a vote of no confidence but insisted a referendum must be held prior to a general election. The SNP did not dismiss the prospect but called for labour to move first with the immediate threat of a no-deal exit.

Meanwhile, markets are increasingly operating on the assumption that the UK is heading towards a no-deal Brexit. On Wednesday, the European Central Bank blasted UK-based lenders for their failure to adequately prepare for Brexit, calling on them to move additional staff and resources to the European Union before October 31.

The ECB also requires banks to hold enough funds to ensure they can absorb potential losses at their European units.

Boris Johnson has repeatedly said that he wants the UK to leave the EU with a deal, but the UK must leave “do or die” by October 31st.