Theresa May is facing growing Brexit pressure on multiple fronts as Tories challenge her renegotiation stance and fresh questions about the impact on the economy arise.
Conservative rebels in the Lords will back opposition parties to inflict a second Brexit Bill defeat in as many weeks on Tuesday, this time over a vote on the final deal.
Sinn Fein’s surge in the Northern Ireland elections on an anti-Brexit ticket could see Stormont become more critical about the EU split.
And the expected sale of Vauxhall this week will see concerns over the 4,500 linked British jobs – and the UK car manufacturing sector as a whole – re-enter the spotlight.
The battles are emerging with just weeks left for Mrs May to hit her self-imposed target of triggering Article 50 and starting Brexit talks by the end of March.
Number 10 remains confident that MPs and peers will pass the Article 50 Bill in good time to start the two-year negotiations as planned.
However the Prime Minister is under growing pressure to offer a reassurance that the 3 million EU citizens living in the UK will be allowed to work and live here after Brexit.
Mrs May has insisted that such a promise should only be made if Brussels make the same pledge for the 1.2 million Britons currently living on the Continent.
But in a significant intervention, the cross-party Commons Brexit Committee uses a report published on Sunday to demand Mrs May issues a “unilateral” guarantee to EU citizens.
The call carries weight because leading Tory Eurosceptics including Michael Gove, the former justice secretary, and Dominic Raab, a former minister, have approved it.
Hilary Benn, the former shadow foreign secretary and chairman of the committee, said: “EU citizens who have come to live and work here have contributed enormously to the economic and cultural life of the UK. They have worked hard, paid their taxes, integrated, raised families and put down roots.”
He added: “EU nationals in the UK and UK nationals in the EU are aware of the forthcoming negotiations, but they do not want to be used as bargaining chips. Although the Government has said it wants EU citizens to be able to remain, this has not offered sufficient reassurance that the rights and status that they have enjoyed will be guaranteed. It should now do so.”
One Eurosceptic committee member told this newspaper that while they backed the call it should not be written into law, as Labour and the Liberal Democrats have called for.
The source argued that more pro-EU demands were removed from the committee’s report as members sought to find recommendations they could all agree on.
The committee also brands the process for EU citizens applying for permanent UK residence, which includes completing a 85-page form, “not fit for purpose”.
The MPs demand an “urgent” change to the procedures amid fears it would take “the equivalent of 140 years” to process all eligible applicants. Brexit talks will last only two years.
It also calls for the Government to consider giving EU migrants “preferential access” to the UK after Brexit – something leading Eurosceptics rejected during the referendum campaign.
The Government faces a second damaging defeat in the House of Lords in as many weeks on Tuesday. Peers last week voted through an amendment backing a reassurance for EU citizens.
Labour and Liberal Democrat peers have attracted enough Tory and crossbench support for an amendment giving Parliament an effective veto on the final deal.
Under the proposal, failure to get the approval of both peers and MPs for the terms of exit would bar Britain from leaving the EU.
If the amendment is voted through as expected on Tuesday it will be up to MPs whether to approve the change or reject it.
Ministers are privately confident the Commons will reject any amendments approved by the Lords.
They have warned that failure to do so could see the final Brexit deal ending up in the Supreme Court.
“Having an amendment on the face of the Bill means you run the risk of ending up in the Supreme Court again. That is the last thing we want,” said a senior Government source.
In the Northern Ireland elections, Sinn Fein – who oppose Brexit – increased their vote share by 4 per cent while the Eurosceptic DUP dropped support.
The result has raised fresh questions about the future of the UK as well as whether Stormont will be more forensic in its scrutiny of Brexit in the coming weeks.
Coalition talks will now take place to try and form a new executive. UK Government sources downplayed the significance of the result on the progression of Brexit.
This week France’s PSA Group, maker of Peugeot and Citroen cars, is expected to announce a deal with General Motors to buy its Opel and Vauxhall brands.
Ministers including Theresa May have been holding talks with senior figures in both companies to ensure that the 4,500 British jobs in two UK plants will continue.
It is likely to put the impact of Brexit on the UK car manufacture industry, and in particular the possibility of new tariffs with EU trade, back in the spotlight.