Liberal Democrat president Simon Hughes has long been a darling of the party's membership.
To the left of many Lib Dem MPs on most social and economic issues, he has represented the inner-London constituency of North Southwark and Bermondsey - previously a Labour stronghold - since 1983.
Mr Hughes took the seat in a notoriously bitter by-election, beating Labour's Peter Tatchell.
In one election leaflet, the Liberals presented him as the "straight choice" against the gay Mr Tatchell. Mr Hughes has said he hopes there will never be that sort of campaign again.
Job: Party president
Educated: Llandaff Cathedral School, Cardiff; Christ College, Brecon; Selwyn College, Cambridge; Inns of Court School of Law; College of Europe, Bruges
Before politics: Barrister
Key quote:"I believe that the Liberal Democrats have huge potential for winning big in the future."
What the papers say: "A left winger who polled a close second place behind Charles Kennedy in the last leadership election, he is seen as too woolly and disorganised by economically liberal Lib Dem MPs," Financial Times
He recently denied being gay in a newspaper interview but has now admitted having both homosexual and heterosexual relationships in the past, and to phoning a gay chat service.
Mr Hughes said he hoped his admission did not disqualify him from doing a good job in public life and regretted being "defensive" when he denied being gay.
Despite his high profile, Mr Hughes came second to Charles Kennedy in the 1999 Lib Dem leadership contest.
The 54-year-old has repeatedly said he would never run against Mr Kennedy, reiterating the point as recently as last September.
But he was free to enter the forthcoming contest following Mr Kennedy's resignation.
However, Mr Hughes, despite his popularity among the membership, is not thought to command such widespread support among Lib Dem MPs.
He became the party's home affairs spokesman in 1999, using that position to articulate the same liberal views he has consistently held on such issues as penal and asylum policy.
But he gave up the post to be a candidate in the 2004 London mayoral elections, where he came third.
In September the same year he was elected president of the Liberal Democrats.
He is a keen advocate of proportional representation, arguing that the Lib Dems would have 150 - rather than the current 62 - MPs under a "fairer" election system.
In July last year, he was also appointed as the Liberal Democrat shadow to the attorney general.