Sir Graham Brady, chairman of the party's backbench 1922 committee, has suggested the prime minister is close to overcoming objections to the unpopular Northern Irish backstop.
"The possibility that monetary tightening might be needed in the future does not necessarily mean we need to tighten now", Saunders said in a speech at Imperial College in London. "The attorney general needs to give a legally binding guarantee that the backstop is temporary".
Britain is due to leave the European Union in 24 days, but parliament's rejection of May's deal earlier this year has put in doubt how, when or possibly even if Britain's biggest foreign and trade policy shift in more than 40 years will take place.
The Brexit deal of PM May was rejected in Brussels by a large majority of the lawmakers last January.
The opposition Labour party yesterday accused Conservative Prime Minister Theresa May of attempting to 'bribe lawmakers into supporting her Brexit deal, after she promised extra funds for economically deprived areas of England.
The third requirement is "a clear exit route" such as an end date or a unilateral exit mechanism for the United Kingdom to leave the backstop.
Northern Ireland is heavily dependent on cross-border trade with the Irish Republic.More news: Trump Blames Democrats for Failed Summit With Kim Jong Un
Asked after a meeting of senior ministers whether May had set out specific details of what Cox was seeking, her spokesman said: "No ... you can expect them (Cox and Barclay) to be having detailed discussions around the legally binding changes we're seeking to the backstop, but it wasn't discussed at cabinet".
May's Chief Whip Julian Smith, who is charged with trying to rustle up enough support for her plan in Parliament, told her top ministers Tuesday that the vote next week will be tight, according to three people who spoke on condition of anonymity. If that is rejected, there will be a vote on no-deal, and if MPs turn that down, they can vote on whether to delay Brexit. And there are a variety of views within the ERG itself, with some leading figures taking a more hardline approach than others.
Britain now has tariff-free access to European Union markets and it benefits from EU trade deals with other countries.
Britain would scrap 80-90 percent of tariffs on imported goods if it leaves the European Union without a deal but would keep them on sensitive sectors such as cars, beef and lamb, broadcaster Sky News reported on Tuesday.
"I think there are something like 60-70 Labour members of Parliament who feel as strongly as I do against a second referendum", said Flint, who represents an area of Britain which voted to leave the European Union at the 2016 referendum.
"I think there is something like 60 or 70 Labour MPs who feel as strongly as I do against a second referendum, but also I think it's important to recognise that many of those MPs also feel that we have to move on, we have to stop a no-deal and if there's an improved offer on the table, then Labour should engage with that sincerely", she added.
Labour's shadow chancellor John McDonnell said the proposal "smacks of desperation from a government reduced to bribing MPs to vote for their damaging flagship Brexit legislation".