Ministers are in private negotiations with senior Conservative backbenchers to smooth the way for Article 50 to be triggered as soon as Tuesday.
Pro-European MPs have told whips that they want David Davis, the Brexit secretary, to pledge that parliament will have a “meaningful” vote on any deal with the European Union when he opens the Article 50 debate on Monday.
They also want him to reiterate the government’s intention to protect the rights of EU citizens living in the UK if no deal is reached.
They have made clear that if concessions are made on these two points they will vote against the amendments to the bill that have been passed by the Lords. That would allow Theresa May to trigger Article 50 the following day when she makes a statement to parliament on the European Council meeting held this week.
Downing Street insisted last night that no final decision had been made on the timing. They played down speculation that Mrs May could make an announcement on Tuesday.
One senior Tory backbencher said they wanted to “work with the government” to get reassurances on parliamentary scrutiny and avoid a confrontation when the bill returns to the Commons on Monday.
“We’re not there yet but the ministers are certainly listening to us and treating us well,” said one.
Senior government sources acknowledged that there were talks and suggested that Mr Davis would make an effort to “reassure” MPs on Monday.
However, it is understood that a sticking point is parliament’s role should a future deal with the EU not be agreed.
Ministers have made clear that they want a “clean” unamended Article 50 bill to be passed by parliament and expect to overturn the changes to the bill inserted by the House of Lords.
Privately Labour has accepted that they “do not have the numbers” to force the amendments through. They are understood to have had private talks with pro-European Tories to see how they can force the maximum concessions out of the government.
“There have certainly been talks going on,” one source said.
If the Commons overturns the Lords amendments the bill will return to the second chamber where it is likely to be passed, possibly as early as Monday night. That would clear the way for the prime minister to trigger Article 50 as soon as Tuesday.
In preparation for the talks, the government moved yesterday to strengthen the British negotiating team with the appointment of Simon Case, who works as Mrs May’s closest civil servant in Downing Street, to a new role in Brussels.
Mr Case, Mrs May’s principal private secretary in No 10, will take up a newly created position as director-general for the UK-EU partnership.