KEN Livingstone has also been embroiled in controversy in the past over his views on Northern Ireland.
An advocate of Irish reunification, during the 1980s he met with the mother of hunger striker Thomas McElwee and publicly proclaimed his support for the prisoners on hunger strike.
He was heavily criticised for the meeting and soon after also met with the children of Yvonne Dunlop, a Protestant killed when McElwee took part in bomb attacks on Ballymena in 1976.
Mr Livingstone also agreed to meet Gerry Adams who had been invited to London by Labour members of the Troops Out campaign in December 1982.
The same day as the invitation was made, the INLA bombed The Droppin Well bar in Ballykelly, killing 11 soldiers and six civilians.
Mr Livingstone insisted the meeting proceed, but Conservative Home Secretary Willie Whitelaw banned Adams' entry to Britain.
In February 1983, he visited the Sinn Fein leader in west Belfast, receiving a hero's welcome from local republicans.
The following year, not long after the Brighton bomb, Mr Livingstone and Jeremy Corbyn broke ranks with other Westminster politicians to invite Mr Adams to speak in London.
He was also heavily criticised for a radio interview proclaiming Britain's 800-year occupation of Ireland was more destructive than the Holocaust.
His republican sympathies saw him come within days of being assassinated in the 1980s by loyalist paramilitaries.
