It comes amid disagreement over the Northen Ireland protocol.
Northern Ireland's First Minister has been told he'll have to resign when a new DUP leader is elected.
Paul Givan was nominated to the role on Thursday by Edwin Poots, who later resigned as leader.
Hundreds of people protested in Co. Down last night, calling on the DUP not to put forward a new First Minister until the Northern Ireland Protocol is scrapped.
Michael Nesbitt, MLA for Strangford and former leader of the Ulster Unionist Party says it'll take time for that to happen.
"If it's going to go, it's going to be through a process of negotiation. And that has to be led by the British government and the EU."
"One of the problems was it was done soo quickly... and nobody thought through the consequences," he said.
Edwin Poots stood down as leader after just 21 days in the job.
It follows a revolt within the party over a deal with Sinn Fein and the British government on Irish language laws.
DUP representatives had not backed the decision to nominate Paul Givan as First Minister.
