THE dark bags under her eyes said it all.

Still reeling from her second cabinet resignation in less than 24 hours, Theresa May entered the Commons to defend her Brexit plans to a short burst of cheers from the Tory benches.

But it wasn’t long before Conservative in-fighting broke out into the open, leaving the Prime Minister forced to deny Friday’s Chequers agreement was a "betrayal".

Peter Bone – an long-time opponent of the EU – faced shouts of "shame" and "nonsense" from his own party as he revealed local activists had refused to campaign over the weekend because they were so disillusioned.

He was heckled as he added: "They said they were betrayed and they asked, 'Why do we go out each and every Saturday to support the Conservative Party and get MPs elected?'

"For the first time in over 10 years, that group refused to go out and campaign.”

Andrea Jenkyns, another prominent Tory Eurosceptic, insisted she had received hundreds of emails from furious activists.

“Within 48 hours of the Prime Minister’s statement on Friday, I received over 300 emails—disheartened, dismayed and telling me that democracy is dead,” she said.

Elsewhere, former Tory minister Sir Edward Leigh raised fears Mrs May’s Brexit compromise would “severely constrain our ability to make our business more competitive and to undertake free trade deals”.

And another former minister, John Redwood, asked the PM to "clear away the ambiguity or contradictions in the Chequers statement” which implied “we might accept [EU] laws and we might have their migration policy".

Mrs May was left insisting her negotiating position, apparently agreed by her Cabinet on Friday, was not a betrayal of 2016’s referendum result.

She told MPs: “We will end free movement, we will end the jurisdiction of the European Court of Justice, we will stop sending vast sums of money to the European Union every year, we will come out of the Common Agricultural Policy, we will come out of the Common Fisheries Policy.

"I believe that is what people voted for when they voted to leave and we will deliver in faith to the British people."

Earlier, from the opposition benches, an ashen-faced Mrs May was left facing down something just as deadly as party in-fighting: ridicule.

There were howls of laughter as she paid tribute to former Brexit and foreign secretaries David Davis and Boris Johnson.

She insisted she wanted to recognise the “passion” Mr Johnson demonstrated “in promoting a global Britain to the world as we leave the European Union”.

“What we are proposing is challenging for the EU,” she later added, to yet more guffawing. “It requires them to think again, to look beyond the positions they have taken so far, and agree a new and fair balance of rights and obligations.”

The PM tried to join in with the mirth when Labour leader Jeremy Corbyn rose to stick the boot in. Her smile was pained.

“Two years on from the referendum, 16 months on from Article 50 being triggered, it’s only this weekend that the Cabinet managed to agree a negotiating position among itself,” Mr Corbyn thundered. “And that illusion lasted 48 hours.”

He added: “On Friday the Prime Minister was so proud of her Brexit deal that she wrote to her MPs to declare that collective Cabinet responsibility ‘is now fully restored’, while the Environment Secretary [Michael Gove] added his own words, saying that ‘one of the things about this compromise is that it unites the Cabinet’.”

On the SNP benches, Westminster leader Ian Blackford congratulated Mr Davis “on the whole four hours that he spent negotiating in Brussels”.

But he reserved his harshest criticism for Mr Johnson. The departing Foreign Secretary should not have been allowed to resign, he insisted – "he should have been sacked for being a national embarrassment.”