Three days of voting in Britain’s parliament culminates Thursday with lawmakers deciding whether to ask the European Union for a delay in Britain’s exit from the bloc.

The House of Commons overwhelmingly voted against Prime Minister Theresa May’s negotiated terms for Brexit on Tuesday, and it followed that with another vote Wednesday rejecting the possibility of leaving the EU on March 29 with no deal in place.

If Thursday’s extension measure passes, it would need further approval from the other EU members in order to go forward.

EU officials have repeatedly said they would need proper justification to agree to pushing back the deadline. And after Wednesday’s vote they said that while it is one thing for the British government to reject a so-called no-deal exit, at some point they would have to figure out the alternative, a deal they could actually pass.

The EU also prefers any extension be limited, finishing before its own elections in late May.

European Council President Donald Tusk left open the possibility of a longer delay, saying Thursday that ahead of a meeting of EU leaders next week he would be appealing to member states to consider that option if Britain “finds it necessary to rethink its Brexit strategy.”

May brought what she said was an improved deal to parliament for Tuesday’s vote, one that sought to remove concerns about the border between Northern Ireland and EU member Ireland. Opponents want to make sure Britain is not locked into a long-term customs agreement that subjects the country to EU trade rules.

May hinted Wednesday that she could try for a third time to get lawmakers to approve the deal that negotiators from Britain and the EU worked on for two years.

The Wednesday vote rejecting a no-deal exit does not carry legal weight, only political force, meaning it is still possible that without an extension and without an agreement during the next two weeks, Brexit could proceed with no divorce terms in place.