British lawmaker yesterday began debating a landmark bill to end Britain's membership of the European Union, with Prime Minister Theresa May gearing up for a major battle.
The bill provides for the repeal on Brexit day of the 1972 European Communities Act that conferred Britain's membership, and also converts estimated 12,000 existing European regulations into British law.
Ministers say it is the first step in implementing last year's referendum vote for Brexit, and will provide legal continuity to ensure no "cliff-edge" when Britain leaves the bloc in March 2019.
But critics warn it represents an unprecedented "power-grab" by giving the government broad powers to amend the EU laws as they are transferred without proper parliamentary scrutiny.
A House of Lords committee said it "weaves a tapestry of delegated powers that are breath-taking in terms of both their scope and potency", and the opposition Labour party has vowed to vote against it.
May's Conservative party lost its majority in the House of Commons in a snap election in June, but her alliance with Northern Ireland's Democratic Unionist Party means the first stage of the bill should pass.
However, she is vulnerable to rebellions on her own side as the legislation comes under detailed scrutiny in the coming weeks, while at least seven more Brexit-related bills are expected before Britain leaves the EU.
Cabinet divisions over one of the most contentious issues of Brexit, immigration, emerged this week following the publication of a leaked report proposing restrictions on EU workers once Britain ends free movement of labour.
Interior minister Amber Rudd was said by several newspapers to be unhappy with the plans, which have been condemned by several business groups as too tough.
Meanwhile in Brussels, negotiations with the EU on the terms of the divorce are progressing slowly, threatening Britain's hopes to move on to talks on a future trade relationship within weeks.
May said Thursday that the Repeal bill was "the single most important step we can take to prevent a cliff-edge for people and businesses, because it provides legal certainty" after Brexit.