Theresa May's government pulled the trigger on all no-deal Brexit planning on Tuesday.

Ministers agreed yesterday to spend an extra £2 billion on measures like reserving ferries for medicine and food to prepare for a no-deal outcome.

However, a number of Cabinet ministers are opposed to it.

In the last 24 hours leading MPs have said they will quit the Conservative party if the government pursues no deal.

Health Select Committee Chair Sarah Wollaston plus ex-ministers Anna Soubry and Nick Boles said they'd resign the Conservative whips.

LONDON — A handful of leading Conservative MPs have publicly vowed to quit the party if Theresa May's government tries to leave the European Union without a deal.

More have told Business Insider that they privately plan to do the same.

Government ministers on Tuesday agreed to begin no-deal planning in full, now that May's Brexit deal is almost certain to be voted down by MPs next month. Time is also running out ahead of the UK's March 29 departure date from the EU.

The plans include an additional £2 billion for government departments, and a move to reserve space on ferries to ensure that medicine supplies don't run out in the immediate aftermath of a no deal scenario.

Defence Secretary Gavin Williamson also revealed that 3,500 British troops were "at readiness" to intervene. Some have predicted civil unrest and food shortages if the UK leaves the EU without a Withdrawal Agreement.

Nick Boles MP, a former minister under David Cameron, said on Tuesday that he'd quit the Conservatives if no deal becomes government policy.

He tweeted: "If at any point between now and 29 March the government were to announce that ‘no deal’ Brexit had become its policy, I would immediately resign the Conservative whip and vote in any way necessary to stop it from happening."

Anna Soubry MP, a leading pro-EU MP and former business minister, supported Boles, tweeting: "You, me and other moderate One Nation Tories. Country must come before party allegiance." She later told Channel 4 that she would quit the Conservatives if May pursued the "utter madness" a no deal Brexit.

"I'm not going to hang around in the Conservative Party by keeping on with the whip if we embark on this madness and I know I'm not alone in that," she said.

Their Conservative colleague Sarah Wollaston then became the third MP to make a public resignation threat, tweeting: "I could not remain a member of the Conservative Party if PM changed her main policy objective to delivering No Deal and No Transition.

"No responsible government could knowingly aim to inflict that kind of harm on the people & especially when we are so woefully unprepared."

Sarah Wollaston MP. BBC

Other Conservative MPs have told Business Insider they would consider resigning if no deal became government policy.

Downing Street insists that ramping up no deal preparation is the behaviour of a responsible government. But a number of Cabinet ministers are strongly opposed to it, and want the no deal option taken off the table.

Justice Secretary David Gauke reportedly told yesterday's Cabinet meeting that no deal was a "unicorn that needs to be slaughtered," while Home Secretary Amber Rudd allegedly said: "Just because you’ve put on a seatbelt doesn’t mean you have to crash the car."

The EU is set to publish its own no deal planning on Wednesday morning after refusing to re-open negotiations on the Withdrawal Agreement at a summit in Brussels last week.