Tory MPs have ramped up pressure on ministers to quit the government over Brexit, warning they will be “complicit in delivering no-deal” unless they resign by the end of the month.

Politicians backing the so-called People’s Vote campaign for a second referendum told ministerial colleagues it was time to “look into their hearts” and “step up to the plate” to stop Theresa May taking Britain out of the EU without an agreement in place.

They spoke out as attention turns to the February 27 Commons votes billed as “high noon” for Brexit.

One of the MPs, who did not wish to be named, and another source said up to 25 ministers were considering whether to quit to back an amendment put forward by Labour’s Yvette Cooper and Tory Oliver Letwin, which would allow the Commons to block a no-deal Brexit.

Tory MP Sarah Wollaston told HuffPost UK it was time for ministers to finally follow through on threats to walk away, describing it as their last chance to take control of Brexit, with time running out to pass legislation to overturn the March 29 EU exit date and extend Article 50.

The Totnes MP said: “We’ve been saying this for some time, that it’s high noon, but really I’m afraid if they are not prepared to do it next time round, when will they be prepared to do it?

“I’m afraid by the next time it comes back, if they are not prepared to step up to the plate, then frankly people will be asking them why not.

“They will be complicit in actually delivering no-deal if they are not prepared to take a stand then.”

Another MP said ministers must now realise May’s “real plan B” if her deal is rejected by hard Brexiteers is to pivot to no-deal.

“I never thought that was possible up until Christmas, but since Christmas I thought it is,” they told HuffPost.

“Anybody who doesn’t resign at the end of the month is embracing no-deal as far as I can see, which is a position.

“Anybody who stays onboard the ship is facilitating no-deal.”

Tory Heidi Allen, meanwhile, seized on business secretary Greg Clark’s warning that the effective deadline for a Brexit deal is in fact around now, because exporters need to know what trading terms they are facing before sending goods on a six-week journey to east Asia.

“(Ministers) have been unable to influence from inside so their country needs them now and they need to stand up,” she said.

“There are already goods that are en route to the Far East that will be in a tariff no man’s land.

“They must look into their hearts.”

Wollaston also suggested she was coming close to quitting the Conservative Party, having previously warned she would sit as an independent if no-deal became government policy.

“I am already considering my position,” she said.

“There comes a point where running the clock down becomes the same as an effective government strategy for no-deal.

“We are certainly nearing that point.”

People’s Vote supporters are expected to back the approach proposed by Labour’s Peter Kyle and Phil Wilson – to back May’s deal in return for a second referendum to give the public the final say.

But Allen conceded other options would first have to be swept off the table before a fresh vote could command a Commons majority.

“Although there are some rumours that she would put forward her deal subject to a People’s Vote, that would certainly have support,” she said.

“I think if high noon is in two weeks time, I can see ministers resigning then, but trying to force her to the sort of thing Jeremy Corbyn has opened the door to – [a] customs union – and only then, when that fails, will it be a People’s Vote.”