Rebel Tory MPs opposed to Theresa May’s Brexit plans will not be able to push a rival ‘no deal’ scenario through the Commons, ministers are set to warn.

In a major bid to pile pressure on to Eurosceptic hardliners, backbenchers are to be told that Labour and other opponents will be able to use a string of Government bills to block any attempt to crash out of the EU without agreement, HuffPost UK has discovered.

Senior Government figures believe that if MPs vote down May’s compromise Brexit plan next month, the Trade Bill, Immigration Bill, Fisheries Bill and the Withdrawal and Implementation Bill would then all be ambushed by amendments to make ‘no deal’ impossible. 

A customs union with the EU, as well as a delay to Exit Day itself, are among the options that have more than enough cross-party support to overcome May’s narrow majority, ministers believe. 

One Cabinet minister said the real “peril” for Brexiteers was that the only realistic alternatives to the PM’s plan would all involve a ‘softer’ Brexit.

The Trade Bill, currently being deliberately held up in the House of Lords by worried ministers, is the most immediate concern within Whitehall after a close shave in the Commons this summer.

A cross-party amendment committing the UK to a customs union with the EU was defeated by just six votes.

Tory ‘Remainers’ teamed up with Labour, SNP and other parties and are likely to do so again.

“It only takes three people to switch position and since then we’ve had two ministers quit the Government [Jo Johnson and Philip Lee] who have come out against the PM’s plans,” one source said.

Another senior source said that if MPs believed there was any risk of a no-deal outcome the Trade Bill would be the first line of defence. “On any customs union amendment, we won’t just lose. We will lose by more than 40 votes,” they said.

The Immigration Bill, due in the New Year, would be the next target, together with the Customs Bill. 

Shadow Brexit Secretary Keir Starmer has reassured Labour MPs privately that the party will do everything in its power to stop a no-deal outcome, with amendments to every piece of Brexit legislation due to be tabled in the next three months.

HuffPost UK understands that Labour is currently talking to Commons clerks about the correct Parliamentary mechanism needed to force the Government to extend the Article 50 deadline which sets March 29 as the UK’s formal exit date from the EU.

A Labour source told HuffPost UK: “We really are in for guerrilla warfare. We mean it. We will throw everything at stopping no deal and we are convinced we can do it.”

New Work and Pensions Secretary Amber Rudd let slip last week that she believed the Commons would stop a no-deal exit, and the Prime Minister refused to contradict her.

Senior members of the Cabinet would rather resign than countenance crashing out with no deal, a move that a new economic analysis claimed would cost billions in lost growth.

One Cabinet minister said: “The peril for Brexiteers is Parliament asking for an extension to Article 50 and the government having to respond to that, as it would become increasingly apparent that a no deal would be a disaster for the country.

“It would be a big gamble by Brexiteers to think we can be timed out and drop out of the EU with no deal. Frankly if this [May’s deal] doesn’t get through the House of Commons the idea of a harder Brexit is absurd.”

May faced yet more opposition to her plans in the Commons on Monday, with former Cabinet ministers Sir Michael Fallon and Owen Paterson stating for the first time that they planned to vote against.

But despite the seemingly impossible odds, several members of the government are confident that Tory MPs will realise there is no feasible alternative plan.

“Facts are like water, they do penetrate even rock that looks not to be terribly porous,” a Cabinet minister told HuffPost.

“Take the transition, a couple of years ago that was unconscionable to most Brexiteers, now it’s preferable if not essential. The whole thing about just-in-time supply chains is now widely accepted.

“The other message that will now permeate is that this deal is the maximum Brexit deal in terms of Eurosceptic compliance.”

Starmer yesterday floated for the first time the idea of an extension to Article 50 becoming Labour policy.  He has long maintained that May is ‘bluffing’ with threats of a no-deal exit.

“I don’t think this Prime Minister would simply plough on regardless, because she knows how dangerous no deal is,” he told BBC Radio 4′s Today programme on Monday.