Jeffrey Donaldson has told Democratic Unionist Party (DUP) colleagues that he intends to run for the party leadership.
Donaldson, a DUP MP for Lagan Valley, wrote a letter to his party colleagues today to confirm the widely anticipated move.
He is expected to make an official announcement later today.
His entry in the race will trigger the first openly contested leadership election in the party’s history.
DUP leader and NI First Minister Arlene Foster last week announced she is to step down as party leader.