Downing Street has said a vote in the House of Commons on proposals for the UK's withdrawal from the EU will be held on 11 December following speculation from some MPs of a delay.
Dozens of Conservative Party MPs have already said they cannot support the proposals despite efforts by British Prime Minister Theresa May to win them round.
Today, Mrs May has sent 30 ministers across the UK to lobby support for her proposed Brexit deal.
Cabinet Office Minister David Lidington is meeting small business leaders in Belfast, where he said the government’s confidence and supply agreement with the DUP continues.
DUP leader Arlene Foster has said a Commons amendment supported by backbench Tories giving parliament a say on invoking the Irish border backstop does not go far enough, adding that domestic "tinkering" to the Withdrawal Agreement would not persuade her party's ten MPs to back the government.
Mr Lidington said: "The DUP have made it clear that they see the confidence and supply agreement as continuing.
"As with any minority government there are going to be squalls and difficulties in a parliament where the government does not have an automatic majority in either House, but that is not something new to British history."
The parliamentary arithmetic is against the British government ahead of next week's withdrawal treaty vote.
Following an amendment, parliament would decide whether to trigger the backstop arrangement or extend the transition period beyond December 2020.
Mr Lidington said MPs have a public duty to act in the national interest, saying all EU leaders have stated that this is the deal that is available.
"So they are not going to move, so the choice becomes if not this deal, what else?
"No other deal is available, therefore it is either crash out, which would do serious damage to businesses large and small, or it is reverse the decision and decide to stay in the European Union after all, which would, I think, come as a heavy blow to very many millions who voted to leave two years ago."
Leaked British government papers have indicated that Ireland could face food shortages and a 7% drop in Gross Domestic Product if the UK leaves the EU without a deal, according to a report by the UK edition of The Times newspaper.
The UK is due to leave the EU on 29 March 2019.
Meanwhile, Britain’s health minister Matt Hancock has warned medical drug companies to expect six months of "significantly reduced access" to the main trade routes between Britain and continental Europe if there is a no-deal Brexit.
In a letter to the health and care sector, published today, Mr Hancock said that government planning assumptions had been "revised" to take into account what happened if the EU imposes import checks on goods from Britain.
He wrote: "These impacts are likely to be felt mostly on the short straits crossings into Dover and Folkestone, where the frequent and closed-loop nature of these mean that both exports and imports would be affected.
"The revised cross-government planning assumptions show that there will be significantly reduced access across the short straits, for up to six months.
"This is very much a worst-case scenario. In a 'no deal' exit from the EU we would, of course, be pressing member states hard to introduce pragmatic arrangements to ensure the continued full flow of goods which would be to their benefit as well as ours".
Yesterday, Mrs May said that MPs faced a choice ahead of a vote on her Brexit deal. They could approval her deal, face an exit with no deal, or even the reversal of Brexit.
She told the BBC: "There are three options: one is to leave the European Union with a deal... the other two are that we leave without a deal or that we have no Brexit at all."
The UK parliament is currently debating Mrs May’s Brexit deal before voting on it next week.
The crucial vote is due to take place on 11 December.