The government is under pressure from the EU to urgently find solutions to break the Brexit impasse by tomorrow.
EU leaders have asked the UK to submit "acceptable" proposals by Friday to break the deadlock over the Irish backstop, which remains the main obstacle to the two sides coming to mutual agreement.
Earlier today, attorney general Geoffrey Cox rejected claims that the UK had not already put forward a plan to resolve the backstop.
"We are discussing detailed, coherent, careful proposals," he said. "We are discussing text with the European Union. I am surprised to hear the comments that have emerged over the last 48 hours that the proposals are not clear. They are as clear as day. And we are continuing to discuss them."
Cox's comments follow an interview Nathalie Loiseau, the French Europe minister, gave to the Guardian in which she said Brussels was "still waiting" for a proposal from London.
"At this stage we know what the UK does not want, and that’s a first phase, but it’s not necessarily enough," she said. "We have not heard proposals, ideas or initiatives coming from the British government to overcome the current difficulties.
Cox also told the House that he would publish the legal advice on any new agreement reached with the EU.
MPs will vote on Theresa May's Brexit deal on 12 March, just two weeks before the UK's scheduled exit on 29 March. If her deal is rejected then MPs will be given a vote on whether they want to leave without a deal or extend Article 50, the mechanism that allows the UK to leave the bloc.
This morning chancellor Philip Hammond urged parliament to get behind May's deal.
"If the Prime Minister's deal does not get approved on Tuesday then it is likely that the House of Commons will vote to extend the Article 50 procedure, to not leave the European Union without a deal, and where we go thereafter is highly uncertain," he told the BBC.
"For those people who are passionate about ensuring that we leave the European Union on time it surely must be something that they need to think very, very carefully about now because they run risk of us moving away from their preferred course of action if we don't get this deal through."
Yesterday the House of Lords doubled down on the pressure facing May when it supported a cross-party bid to keep the UK in a customs union with the EU after Brexit.
The defeat result means MPs will get a chance to vote on whether to stay in the existing customs union when the bill returns to the Commons.