Philip Hammond, the former chancellor who served under Theresa May, says he will vote for the Letwin amendment today.

The Letwin amendment  will provisionally approve Boris Johnson’s deal but also force him to ask for a delay to rule out a no-deal Brexit.

“The Letwin amendment gives us an insurance policy that prevents us having to look at this bill against the constant threat of the government to pull the plug and crash us out on the 31 October,” he says.

Mr Hammond says his fear is that “people who might vote for Boris Johnson’s motion today may then withhold their support later on during the pass of this bill and cause it to crash” – leading to a no-deal Brexit.

Mr Hammond – who served under Theresa May and backed her Brexit deal also says he is open to voting for Mr Johnson’s deal outright – but would be seeking reassurances from the despatch box today.

“I’m absolutely open to supporting the government’s deal, providing the government gives me the reassurances that I’m seeking about the level of ambition in the future partnership and the way that that process will be managed,” he says.