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Theresa May has warned that failure to deliver Brexit would be a "catastrophic and unforgivable breach of trust in our democracy" as MPs plot to sideline the prime minister and take control of the process.
Writing for the Sunday Express today, May says that the meaningful vote on her Brexit deal on Tuesday would be the "biggest and most important decision that any MP of our generation will be asked to make."
She adds that MPs "cannot - and must not - let you (voters) down" and urged MPs "to forget the games and do what is right for our country" ahead of the historic House of Commons vote on her deal with the European Union.
The prime minister is almost certain to lose that vote with MPs on all sides opposed to the Withdrawal Agreement.
The margin of defeat could be over 100 votes, with tens of Conservative MPs and the Democratic Unionist Party that props up May's government set to join all opposition parties in voting against the Brexit deal.
The prime minister is set to return to the Commons within days of a defeat to lay out what she'll do next, with MPs calling for a range of options including a softer Brexit, an extension to Article 50, and a new referendum.
Staunch Brexiteers want May to ditch the controversial backstop for Northern Ireland and negotiate a cleaner break from Brussels, with some calling for a no-deal Brexit.
According to a report in The Sunday Times, a cross-party group of MPs including pro-second referendum Conservative MP Dominic Grieve is planning to take greater control of the Brexit process.
MPs will reportedly try to re-write parliamentary rules to make motions proposed by backbench MPs take precedent over government business, therefore putting what happens next in the hands of MPs.
10 Downing Street fears that this "very British coup" will give pro-Remain MPs greater power to delay Britain's exit from the EU or even put the issue back to the public via another referendum, the report suggests.
A government source is quoted as saying: "Without control of the order paper, the government has no control over the House of Commons and the parliamentary business and legislation necessary to progress government policies.
"The government would lose its ability to govern."
In practice, it would give backbench MPs the power to dictate what legislation is put to Parliament. It would represent a historic enhancement of power for the House of Commons. Tory MP and former Attorney General Dominic Grieve
It goes on to add that Grieve - who has been behind a number of amendments designed to stifle May's Brexit plan - met with House of Commons Speaker John Bercow earlier this week. Bercow infuriated the government this week when he upended constitutional convention to let MPs vote on amendment to a usually unamendable motion.
Grieve refused to deny the reported plans, telling The Sunday Times: "I have no doubt that lots of people may be looking at all sorts of ideas since we are in a deepening national political crisis."
On Friday, Grieve told an anti-Brexit rally that he would do everything in his power to stop a no-deal Brexit, telling campaigners: "Parliamentarians have a responsibility to prevent national suicide and a no deal Brexit would be just that."
His Conservative party colleague, Nick Boles MP, has confirmed that he is working on an amendment that if passed would make it illegal for the government to take the country out of the EU without an exit deal.