LONDON (AP) — Britain’s ruling Conservative party is beginning another week negotiating with itself as it tries to rework Britain’s divorce deal with the European Union before the U.K. leaves the bloc in less than two months.

British Prime Minister Theresa May is gathering pro-Brexit and pro-EU lawmakers from her Conservative Party into an “alternative arrangements working group” seeking to break Britain’s Brexit deadlock.

Starting Monday, the groups is holding three days of meetings with ministers and civil servants to investigate possible changes to the divorce deal rejected by Parliament last month.

The changes center on replacing a measure known as the backstop, designed to keep an open border between Northern Ireland and EU member Ireland.

The EU insists the withdrawal agreement can’t be renegotiated. Britain is due to leave the bloc on March 29.