The treaty, which was based on interim discussions in December, seeks to outline the terms of Britain’s departure from the bloc.

However, one particular flashpoint in the draft — which has prompted anger in Belfast — concerns the protocol regarding a so-called “hard border” between the Republic of Ireland and Northern Ireland.

Barnier said Northern Ireland must remain within the EU’s current rules and regulations post-Brexit. He also underlined this “backstop” agreement had been reached with U.K. Prime Minister Theresa May at the end of last year.

May’s coalition ally in Northern Ireland, the Democratic Unionist Party (DUP), has long criticized this protocol, saying it could create new divisions between it and the rest of the U.K. The DUP has also threatened to revoke its support to Westminster over its concerns of a physical infrastructure being imposed on the Irish border.

The legally-binding text comes just days before May is scheduled to make her most eagerly anticipated speech on Brexit since last year.

However, when May was asked to respond in parliament on Wednesday, she said her government wanted to reach an agreement with the EU that allowed London to have control over its own laws, borders and money post-Brexit.

May also reaffirmed the U.K. government’s position that it did not want a deal that resulted in a hard border between Northern Ireland and Ireland.