Anna Soubry and Chuka Umunna to lead ‘all-party parliamentary group on EU relations’ as Theresa May prepares to publish repeal bill this week

Rebel Tory and Labour MPs have formed a new cross-party group to oppose hard Brexit, as Theresa May prepares to publish her repeal bill this week transposing all EU legislation into British law.

Anna Soubry, the former Tory minister, and Chuka Umunna, the former Labour shadow business secretary, will lead the alliance with other MPs from the Liberal Democrats, the SNP, the Greens and Plaid Cymru in a new attempt to coordinate the parliamentary fight against May’s hard Brexit plan.

The repeal bill is likely to be the first opportunity for the new group, known as the all-party parliamentary group on EU relations, to scrutinise the next phase of Brexit when it is debated in the autumn.

“We won’t accept MPs being treated as spectators in the Brexit process, when we should be on the pitch as active players representing our constituents,” said Umunna, who led the Labour rebellion against leaving the single market last month.

“We will be fighting in parliament for a future relationship with the EU that protects our prosperity and rights at work, and which delivers a better and safer world.”

The repeal bill, due to be published on Thursday, will be a historic piece of legislation reversing the 1972 European Communities Act that took Britain into the bloc, as well as adopting all existing EU standards to ensure a smooth transition.

The prime minister has promised there will be no watering down of workers’ rights or environmental standards, but opposition MPs and rebel Tories fighting for a soft Brexit are likely to try to amend the bill to provide extra safeguards during its passage through parliament.

The bill will be laid on Thursday but will not be debated until the autumn, when there are expected to be tussles in the House of Commons, Lords and devolved chambers.

Labour has said it will attempt to see extra protections for workers and the environment, while other MPs could seek to retain the oversight of cross-EU bodies such as Euratom, even if this means coming under the jurisdiction of the European court of justice.

Some parliamentarians may also seek to limit so-called Henry VIII powers contained in the bill, which will give ministers the right to tweak legislation with minimal parliamentary scrutiny.

This would be needed, for example, to remove references from British law to an EU body that no longer has oversight in the UK, but critics of the powers fear they could be used for deregulation by the back door.