Britain's opposition Labour Party leader Jeremy Corbyn arrives for a meeting with European Union's chief Brexit negotiator Michel Barnier at the EU Commission headquarters in Brussels, Belgium, July 13, 2017. REUTERS/Olivier Hoslet/Pool/File Photo

LONDON (Reuters) - Britain’s main opposition Labour Party said on Tuesday it could not vote for the government’s legislation to sever ties with the European Union unless it was amended to prevent ministers from grabbing powers from parliament.

Parliament will begin debating the EU withdrawal bill on Thursday and there will be a vote on Monday, testing Prime Minister Theresa May’s deal to shore up her majority with the support of a small Northern Irish party.

“Labour fully respects the democratic decision to leave the European Union ... and backs a jobs-first Brexit with full tariff-free access to the European single market,” Labour said in a statement.

“But as democrats we cannot vote for a bill that unamended would let government ministers grab powers from parliament to slash people’s rights at work and reduce protection for consumers and the environment.”