The cabinet will discuss whether the government should ramp up preparations for a no-deal Brexit when it meets later this morning.
It comes after Theresa May said MPs would not vote on her Brexit deal until the third week in January.
Labour leader Jeremy Corbyn has tabled a motion of no confidence in Mrs May, saying she had led the UK into a “national crisis”.
Number 10 dismissed the motion as “silly political games”.
With 101 days left until Brexit and many MPs still opposed to the government’s withdrawal agreement, ministers are due to consider a paper on plans for leaving the EU without a deal.
But a no-deal Brexit is also opposed by many MPs.
A cross-party group of 60 of them have written to the prime minister, saying it would do “unnecessary economic damage”.
Communities Secretary James Brokenshire told the BBC that there would be “consequences” of a no-deal exit but “a lot of work” was going into minimising the disruption if it happened.
“We have been taking no deal seriously for quite some considerable period,” he told BBC Radio 4’s Today.
“It’s not what we want to do, it’s not what we still expect to do… but I think it is right and proper that we maintain our work on preparing for no deal, however reluctantly.”
Health Secretary Matt Hancock told the BBC’s Newsnight that he had ordered full no-deal planning across the National Health Service.
"We’ve instituted full no deal planning within the NHS already, and I would like to see the whole of government going to that position because it’s the responsible thing to do."
— BBC Newsnight (@BBCNewsnight) December 17, 2018
Mr Corbyn, meanwhile, is under pressure to push for a further vote of no confidence in the government as a whole.
On Monday night, he tabled a motion calling on MPs to declare they have no confidence in the prime minister because she failed to have a vote on her Brexit deal straight away.
Mr Corbyn said that, by the week of 14 January, a month would have been wasted since the original 11 December vote was postponed, with “not a single word renegotiated and not a single reassurance given”.
“The deal is unchanged and is not going to change,” he said.
No 10 has refused to make time for the motion.
‘If, not when’
Other parties – the SNP, Lib Dems, Plaid Cymru and the Greens – have called on Mr Corbyn to push for a no-confidence vote against the government as a whole.
Unlike a vote aimed at the prime minister, the government would have to allow a vote on this motion and, if successful, it could force a general election.
Labour’s shadow housing secretary, John Healey, told BBC Radio 4’s Today programme on Tuesday that tabling a no-confidence motion against the government was “a question of when, not if”.
However, Nigel Dodds, deputy leader of Northern Ireland’s DUP, whose votes the Conservative government has relied on in big votes since the June 2017 election, dismissed Mr Corbyn’s move as “parliamentary antics”.
Mrs May also appeared to have the support of pro-Brexit backbench critics who last week failed in a bid to oust her as Tory leader.
One of them, Jacob Rees-Mogg, said he would never vote against Mrs May or a Conservative government in a vote of confidence in the Commons.
“I had my vote of no confidence in her and I lost. I am not going to repeat the exercise,” he told Today, suggesting that the PM was “at greater risk” from Tory MPs who wanted to remain in the EU than Eurosceptics in the party.
On Tuesday, the Daily Telegraph published a letter by 53 business leaders, including former Sainsbury’s boss Justin King and Glastonbury Festival founder Michael Eavis, calling on the prime minister to “take her deal to the British people”.
“The prime minister abandoned the most important vote in the House of Commons for a generation because she knew she could not secure a parliamentary majority for her deal,” they wrote.
They said last week’s rebellion by her own MPs “underlines the impossibility of resuscitating it”.
The prime minister’s Brexit deal sets out the terms of Britain’s exit from the EU – on 29 March 2019 – and includes a declaration on the outline of the future relations between the UK and the EU.
But the deal only comes into force if both the UK and European parliaments approve it.
Mrs May has insisted the EU has listened to MPs’ concerns over the contentious issue of the Northern Ireland border backstop and she hopes to secure additional “political and legal assurances” in the coming weeks about how it might come into force and how the UK could leave it.
But an EU spokesman said it had provided the “clarifications” requested on the backstop and “no further meetings were foreseen”.