Theresa May was given a Brexit boost as key Tories signalled swinging behind her stance in exchange for movement on the Northern Irish backstop.
Chairman of the highly influential 1922 Committee of backbench Tories Sir Graham Brady expressed optimism that a breakthrough on the backstop was close.
The hardline European Research Group (ERG) of Tory MPs led by Jacob Rees-Mogg also indicated a more conciliatory tone on the issue.
The ERG has drawn up “three tests” the Government must pass to win backing, according to the Sunday Times.
In private talks with Attorney General Geoffrey Cox, the ERG called for a legally-binding mechanism to escape the backstop, with a clear exit route and an unambiguous rewrite of the language in the Government’s legal advice, the newspaper said.
The stance has been drawn up in conjunction with the DUP, according to the Sunday Times.
Brady made clear he could swing behind the Prime Minister’s Withdrawal Agreement ahead of crunch Commons votes.
Writing in the Mail on Sunday, Brady said: “The whole country is tired of vacillation and delay.
“When the right compromise is offered, we should pull together behind the Prime Minister and help her to deliver our exit from the European Union on March 29.”
Many Brexiteers have expressed opposition to the backstop as it would leave the UK obeying EU customs rules if no wider trade deal is agreed after a transition period.
Sir Graham, who branded the Government’s handling of the Brexit negotiations as “lions led by donkeys”, indicated there was a growing mood for a deal in the Commons.
He said: “My conversations with senior diplomats and politicians from across Europe have given me cause for optimism that a breakthrough is near.”
The ERG proposals were drawn up by eight members, including veteran Euro-sceptic Sir Bill Cash, the Sunday Times said.
One of the eight, Michael Tomlinson, told the newspaper they needed to see “black and white” text in good time before the Commons votes.
Tomlinson told the Sunday Times: “There is a spectrum and a range of options that the Attorney General has.
“I’m going to say protocol good, codicil bad, letter very bad, because that would be prejudging it.”
The manoeuvring follows May telling MPs the Commons will have a “meaningful vote” on her Brexit plans by March 12.
The PM said that if her deal is rejected, MPs will be able to vote on whether the UK can leave the EU in a no-deal scenario, and if that is rejected, the Commons can decide on whether to extend Article 50 and delay Brexit.
Meanwhile, EU chief Brexit negotiator Michel Barnier said he does not believe the UK will have enough time to approve May’s withdrawal deal by the scheduled exit date of March 29.
Barnier suggested a “technical extension” of up to two months may be needed.
Asked if he thought it was possible to reach an agreement by March 29, even if Westminster gave the green light this month, Barnier told Spain’s El Mundo newspaper: “No.”
Barnier has also stated that Brussels is ready to give the UK further “guarantees, assurances and clarifications” that the Irish backstop should only be temporary.