LONDON (Reuters) – Britain will hold its first full parliamentary debate on Sept. 7 on legislation which will sever the country’s ties with the European Union, the leader of the lower House of Commons, Andrea Leadsom, said on Thursday.

The repeal bill is central to the government’s plan to exit the EU in 2019, disentangling Britain from more than 40 years of EU lawmaking and repealing the 1972 treaty that first made Britain a member.

The legislation was published earlier this month but members of parliament were not given an opportunity to debate it.

Leadsom said the legislation would be given its “second reading” in parliament on Sept. 7 and Sept. 11. At the end of this two-day debate, parliamentarians will vote on whether to allow the bill to proceed to the next stage.

At the second reading lawmakers are asked to agree to the principle of the legislation. Their first opportunity to put forward amendments to the bill, either proposing changes or adding new clauses, comes at a later stage.

The legislation’s passage through parliament could make or break Theresa May’s future as prime minister after she lost her outright parliamentary majority at last month’s election, reopening the debate on the nature of Brexit.