On Tuesday and Wednesday, the government will try to alter or reverse the changes in the House of Commons. But it's facing a potential rebellion from some Conservative lawmakers who want to retain close ties with the bloc after Britain leaves in March 2019.
They are rallying around a move to give the House of Commons power to send the government back to the negotiating table with Brussels if lawmakers don't like the terms of the Brexit deal struck with the EU. Currently, the government is offering lawmakers a "take it or leave it" vote on the final deal.
May is due to address Conservative legislators Monday to try to quell a rebellion by pro-EU Tories. Her office said she would stress the need to show "that we are united as a party in our determination to deliver on the decision made by the British people."
In fact, her party is far from united over the decision to leave the EU. May's Cabinet is divided between ministers including Foreign Secretary Boris Johnson, who support a clean break with the EU, and those such as Treasury chief Philip Hammond who want to keep close ties with the bloc, Britain's biggest trading partner.
Britain is due to leave on March 29, 2019, and the bloc is frustrated with what it sees as a lack of firm proposals from the U.K about future relations. May's spokesman James Slack said Monday that a promised document setting out the government's negotiating position would not be released before a June 28-29 EU summit, as previously planned.
Amid the uncertainty, business concern is mounting. Three major German business organizations on Monday pressed for clarity from Britain on its plans for a post-Brexit relationship with the EU. Dieter Kempf, the head of the BDI industry lobby group, said that "our companies must have clarity by October for their plans after Brexit day."
His counterpart at the BDA employers' association, Ingo Kramer, said that after Brexit German companies must be able to send employees to U.K. branches in just as "uncomplicated" a way as British companies can to the EU.