Former SDLP leader John Hume is expected to stand down as a Euro MP at a press conference in Belfast today.
The 67-year-old Foyle MP who has been an MEP since 1979 has refused to confirm the move but party sources are indicating his intention to quit.
His health has deteriorated over the past few years and his family apparently want him to scale down his workload.
Despite putting his name forward for the European elections in June, he is expected to follow his DUP rival the Reverend Ian Paisley who last month announced his withdrawal from the poll.
Mr Hume came close to defeating Mr Paisley in the last European election in 1999. If, as expected, he does stand down, it will be the latest move in a gradual retirement from Northern Ireland politics.
In 2000, Mr Hume left his seat in the Northern Ireland Assembly and a year later stood down as leader of the SDLP, a post he held since 1979.
In 1998, he was awarded the Nobel Peace Prize along with Ulster Unionist leader David Trimble for his work in helping to bring about the Good Friday Agreement.