The commitment is an attempt to gain backing from opposition Labour Party MPs, who suspect the government plans to reduce the protections after Britain leaves the EU.
May’s deal has drawn opposition from both pro-EU and pro-Brexit lawmakers, and is facing likely defeat in Parliament today.
The prime minister used a speech yesterday to argue that the only alternatives to her deal were leaving the EU in March without an agreement, or reversing voters’ decision to leave the bloc. May said that a no-deal Brexit would hurt the British economy and “put the future of our Union at risk”, while failing to leave the EU would be “a subversion of the democratic process”.
Meanwhile, Manfred Weber, a German conservative who heads the biggest group in the European Parliament, has urged British MPs to “behave responsibly” and approve the UK’s divorce deal with the EU.