London(CNN) Britain's defense secretary announced that 3,500 troops will be on standby for a possible no-deal Brexit, as lawmakers said Tuesday that they have ramped up preparations for leaving the European Union without an agreement.

With just 101 days to go before the UK is due to leave the EU, Cabinet members have made no-deal planning an "operational priority," Brexit Secretary Stephen Barclay said.

Families and businesses will be sent official advice over the coming weeks on how best to prepare for such an outcome, a Downing Street spokeswoman told CNN.

After a Cabinet meeting on Tuesday, Prime Minister Theresa May's official spokesman said ministers agreed that an emergency contingency plan was essential in case parliamentarians reject her deal when they vote on it in January.

May's official spokesman said Cabinet ministers agreed that an emeregency no-deal contingency plan was essential.

The spokesman stressed, however, that the government's "top priority" is to deliver the prime minister's deal, adding that it remains "the most likely scenario."

Defense Secretary Gavin Williamson told the House of Commons Tuesday that 3,500 troops will be ready to support the government in case of a no-deal Brexit.

"We've as yet not had any formal request from any government department but what we are doing is putting contingency plans in place," Williamson told the Commons.

"What we will do is have 3,500 service personnel held at readiness -- including regulars and reserves -- in order to support any government department on any contingencies they may need."

Gavin Williamson, left, told the House of Commons on Tuesday that 3,500 troops will 'held at readiness' in case of a no-deal Brexit.

According to the UK's Press Association news agency, Barclay said after the Cabinet meeting: "The government's priority remains to secure a deal, but we need to recognize with 14 weeks to go, that a responsible government is preparing for the eventuality that we leave without a deal."

Barclay appealed to UK businesses to plan realistically for a no-deal Brexit.

Downing Street has said that advice will be sent out to households over the next few weeks, and businesses will have access to a 100-plus page document online to help them prepare. Over the coming days, it also said, emails will be sent to more than 80,000 businesses that are most likely to be affected.

"Cabinet also agreed to recommend businesses now also ensure they are similarly prepared, enacting their own no-deal plans as they judge necessary," May's spokesman said.

"Citizens should also prepare in line with the technical notices issued in the summer and in line with further more detailed advice that will now be issued over coming weeks."

May 'leading UK into a national crisis'

The no-deal preparations come as May's proposal remains more deadlocked than ever.

While May has said she will reschedule Parliament's vote on her Brexit deal for the week of January 14, less than 80 days before Britain is due to leave the EU on March 29, opposition leader Jeremy Corbyn called for a motion of no confidence in the Prime Minister.

Corbyn introduced a motion of no confidence in the PM on Monday evening.

He said it was "unacceptable" to make lawmakers wait until January and accused May of "cynically running down the clock" until the UK leaves the EU.

Corbyn also accused May of leading the UK into a "national crisis" as she ignored pleas to abandon her widely criticized deal.

The parliamentary vote on the deal was originally set to take place on December 11, but May delayed it after it became clear she would lose by a significant margin.

The government, however, has refused to allocate time to vote on Corbyn's non-binding, symbolic no-confidence motion, forcing the opposition to decide whether to try to topple the entire administration.

A no-confidence vote against the entire government would have to be scheduled, as it would be binding and could trigger a general election if the government lost.