Colum Eastwood is to step down as SDLP leader at lunchtime today.
Claire Hanna, the MP for South Belfast, is expected to take over the party reins.
Mr Eastwood will “make a personal statement” in Derry about his future after nine years as party leader.
His resignation comes just eight weeks after he retained his Westminster seat with a reduced majority of 4,166.
While the party also retained its seat in South Belfast & Mid Down, the overall general election result was regarded as disappointing for the SDLP, which lost substantial ground in South Down and Upper Bann.
Mr Eastwood has been leader of the SDLP since 2015.
Mr Eastwood is due to speak at a press conference later today.
It is understood that he will remain as leader until a successor is chosen by the party.
A replacement will be named in time for the party’s annual conference in October.
