The Prime Minister is expected to face battles on several fronts at the reading of the Repeal Bill this week, from both a resurgent opposition and within her own party.
MPs supporting a so-called softer Brexit are expected to attach a number of amendments to the bill, which is designed to shift EU law on to the UK’s statute books.
Several MPs are also expected to rebel over plans to quit the European atomic energy treaty Euratom, a move which Theresa May has said is a necessary part of the Brexit process.
Although Euratom is legally distinct from the EU, the agency requires members to come under the jurisdiction of the European Court of Justice, which May has vowed to leave.
Pressure has been mounting since May, celebrating a year as PM this week, included leaving Euratom in her Article 50 letter to the European Council president Donald Tusk.
Conservative MP Ed Vaizey and Labour counterpart Rachel Reeves joined forces at the weekend to draw attention to the issue. A number of other MPs, including Tories Anna Soubry, Nicky Morgan, Nick Boles, Richard Benyon, Bob Neill and Antoinette Sandbach, as well as Labour MPs including Tom Watson and Chuka Umunna, have publicly supported the pair.
May is reportedly now attempting to draw up plans for an approximation of the treaty, saying yesterday that “membership of Euratom is inextricably linked with membership of the European Union”.