Sir Reg Empey has announced his intention to stand down as Ulster Unionist leader in the next few months.
It follows the party's failure to win any seats at the general election, including his own unsuccessful attempt to capture the South Antrim Westminster seat from the DUP.
Sir Reg succeeded David Trimble as party leader in June 2005 following a disastrous general election which saw the party going from having 10 MPs in 1997 to just one.
He inherited a party in turmoil, and while he has not faced the damaging defections which so undermined Mr Trimble's leadership, his party's electoral pact with the Conservatives led to the loss of its sole Westminster representative, popular North Down MP Lady Sylvia Hermon.
With next year's assembly election on the horizon, BBC News looks at five of the main contenders to replace Sir Reg at the helm of the party.
Tom Elliott is a farmer from the village of Ballinamallard, County Fermanagh.
Mr Elliott is a member of the Orange Order who served as a part-time UDR and RIR reservist for 18 years.
As the UUP's candidate for in the 2005 general election for Fermanagh and South Tyrone, he failed to unseat Sinn Fein's Michelle Gildernew, coming third behind the DUP's Arlene Foster.
Before Rodney Connor was chosen by the UUP and DUP as a unionist unity Westminster candidate, Mr Elliott had been pencilled in to run for the Conservatives and Unionists.
The 46-year-old has been an assembly member for Fermanagh and South Tyrone since 2003, and he is vice-chairman of Stormont's agriculture committee.
As a rural-based politician, Mr Elliott could be seen as a candidate who could reconnect with grass-roots unionists outside of urban areas in Northern Ireland where the party polled badly in the general election.
Ulster Unionist deputy leader Danny Kennedy's general election performance stood out in what was a torrid election for the Conservative and Unionist electoral pact.
While the party's share of the vote was down, Mr Kennedy reversed the party's fortunes in Newry and Armagh, outpolling DUP MLA William Irwin and boosting his vote by 5%.
Mr Kennedy has been an assembly member since 1998, and he is a member of the Orange Order.
The 50-year-old is from Bessbrook in south Armagh, a mainly Protestant village in an area dominated by nationalists.
While three out of Belfast's four MPs were once unionist, this has been reduced to just one, suggesting the power-base of unionism has shifted.
Mr Kennedy has the potential to re-engage with the rural unionist community more effectively than East Belfast MLA Sir Reg Empey.
He could be seen as a safe pair of hands as the party attempts to regroup and consider its next move ahead of next year's assembly election.
Basil McCrea emerged from political obscurity in November 2004 when he inflicted a fresh blow to beleaguered then-UUP leader David Trimble.
The Hillsborough businessman heavily defeated Mr Trimble's wife Daphne to win the right to challenge UUP defector Jeffrey Donaldson in the following year's general election.
It was an important seat for the UUP to win, but Mr Donaldson would go on to comfortably see off the challenge of Mr McCrea.
Mr Trimble lost his Upper Bann seat and the UUP leadership as the party was all but wiped out in Westminster, going from five MPs in 2001 to just one.
In the intervening years Mr McCrea has built up a reputation as a polished media performer in his capacity as a Policing Board member and as the party's education spokesman.
However, it is understood the 50-year-old has not built a significant power base within the party, which might hamper any leadership bid.
Mr McCrea was elected to the Northern Ireland Assembly in 2007 and is a councillor in Lisburn.
Michael McGimpsey is the Northern Ireland Health Minister. He was born in Donaghadee, County Down and is a businessman by profession.
In 1986, alongside others he challenged the Anglo-Irish Agreement by bringing a suit against the Irish government in the High Court of the Republic of Ireland.
The case helped to raise the profile of the Unionist cause and the issue of consent which was eventually addressed through the signing of the Belfast Agreement in 1998.
He was elected as a councillor in 1993 and in 1998 he was elected to the Northern Ireland Assembly. Upon devolution he was appointed to serve as Minister for Culture, Arts and Leisure in the first Northern Ireland Executive in 1999.
Mr McGimpsey is thought to be more sympathetic towards the Labour party rather than the Conservatives which is at odds with the electoral pact which could hamper his chances with factions of the UUP.
David McNarry is a senior member of the Orange Order, who said during the Drumcree stand-off in 1998 that the combined forces of unionism could "paralyse the province within hours" if their members were not allowed to march down Portadown's Garvaghy Road.
Mr McNarry has been calling for unionist unity of a different kind in the wake of the UUP's disappointing general election performance.
He certainly did not wait long to cast doubt on the future of Sir Reg Empey's leadership.
The election result in South Antrim was not even confirmed in the early hours of Friday when Mr McNarry said Sir Reg was "finished" as UUP leader.
Appearing as a pundit on BBC Northern Ireland's election coverage, he later said he was "not in the stakes for leadership", but was more interested in unionist unity.
The 61-year-old is an assembly member for Strangford, and sits on a number of committees at Stormont, including the new justice committee.
Just weeks before the election, Mr McNarry dubbed as "weak" the Northern Ireland wing of the Conservative Party, stressing that the UUP's electoral pact did not cover next year's assembly election.
He spoke of the importance of unionist unity to prevent Sinn Fein from taking the post of first minister.