THERESA May insisted Britain will be clean out of the EU “well before” the next general election in a bid to calm a spiralling Tory rebellion.

The PM was forced to endure a painful grilling from her own MPs in the Commons, who accuse her of giving too much ground to Brussels in Brexit negotiations.

Updating MPs on last week’s EU summit, Mrs May dubbed the continuing row with Brussels over how to avoid a hard border in Ireland as “the one real sticking point left, but a considerable one”.

Tackling fury over her suggestion last week for a possible extension to the 21 month transition period, she insisted the move would be “undersirable” and hopefully unnecessary.

She also pledged to rip up the EU’s backstop plan to keep the Irish border open and replace with her own UK-wide option that would not divide up the UK - a movce that will anger the EU.

And both “insurance” options would end “well before the end of this Parliament”, plus the UK would also have a well-defined escape root from both, she insisted.

Appealing for more patience, Mrs May told MPs: “Serving our national interest will demand that we hold our nerve through these last stages of the negotiations, the hardest part of all”.

But the assurances failed to win over Brexiteer backbenchers, who insisted they all be enshrined in binding legal commitments in the Brexit deal.

Former Cabinet minister John Whittingdale fumed at the PM: “It is now over two years since the referendum, and we have agreed that we will not gain control of our laws, borders and money for over four years.

“Does she understand that for many, that is already too long?

Jacob Rees-Mogg, who leads the Eurosceptic European Research Group added: “Does the Prime Minister know where she is going?”

Remainers also attacked her, with former minister Anns Soubry saying small businesses “are in state of despair” because they still don’t know what the UK’s future relationship with the EU will be.

Mrs May also couldn’t offer angry Scottish Tory MPs the promise that she would not trade away Britain’s newly-won back fishing rights in any future trade deal.

In another bid to reassure fretful Cabinet ministers today, Brexit Secretary Dominic Raab will give an update to Cabinet on no deal preparations and insist the emergency planning is on track.

But Mrs May will also be hit by a fresh assault from Boris Johnson on her handling of negotiations.

The ex-Foreign Secretary will use a social media attack advert to brand the PM’s offer to Brussels “a cheat and a fraud.”

The PM did win support from across the Commons over the violent language used about her by anonymous Tory MPs in two Sunday newspapers, who dubbed her as “in the killing zone” told her to “bring her own noose” to a meeting with MPs.

Leading Brexiteer Steve Baker called on Tory briefers to be rooted out and suspended. And prominent Labour MP Yvette Cooper dubbed them “misogynistic”.

Tory MPs’ internal feuding took the party close to breaking point yesterday.

Eurosceptic former minister Mark Francois also blasted No10’s “bunker mentality” and insisted Europe is “laughing at us”.

But that sparked a bitter retaliation from pro-EU Tories.

Antoinette Sandbach accused the hard Brexit European Research Group of “bullying and undermining the PM”.