Conservative leader Michael Howard has announced he is to stand down following his party's election defeat in order to allow a younger person to take over.
Here are some of the names being mentioned as possible successors:
A right-winger who grew up on a council estate, the former Europe minister ran as the "dark horse" candidate in the 2001 leadership contest.
He failed to gather enough support from Tory MPs to make it through to the ballot of party members.
Party chairman under Iain Duncan Smith, he was sacked by phone while on holiday, to be replaced by Theresa May. He was moved to shadow Deputy Prime Minister John Prescott before becoming home affairs spokesman.
Mr Davis is thought to be popular with grassroots Tories and is favourite with the bookmakers to succeed Mr Howard.
SIR MALCOLM RIFKIND
One of the remaining Tory "big beasts", his oratorical skills were quickly recognised by Margaret Thatcher soon after he entered the Commons in 1974.
He was secretary of state for Scotland under Lady Thatcher and then defence secretary and foreign secretary under John Major.
Widely respected across the political spectrum, he has been tipped in the past as a future Conservative leader.
But he lost his Edinburgh Pentlands seat in Labour's landslide election victory in 1997.
He was returned to Parliament earlier this month in Kensington and Chelsea, in place of the retiring Michael Portillo, and was immediately appointed shadow work and pensions secretary.
First elected to Parliament in 1992, Liam Fox soon became a government whip and later a Foreign Office minister when the Conservatives were in power.
The Scottish former GP later ran Mr Howard's successful campaign for the party leadership and was rewarded with the job of party co-chairman - driving media, policy and campaigning issues.
He held the health brief under both William Hague and Iain Duncan Smith and is seen as a convincing frontbench performer.
He pioneered the "patients' passports" policy, which would allow patients to choose where they get treatment or even take 60% of the cost of operations out of the NHS to go private.
In the latest reshuffle, he was appointed shadow foreign secretary.
David Cameron has jumped from policy co-ordinator to shadow education secretary in the latest reshuffle.
He worked on the prime minister's questions briefing team for both Margaret Thatcher and John Major and has since seen a rapid rise through the Tory ranks.
Elected as an MP aged 34 in 2001, Mr Cameron became a shadow minister in the Privy Council Office two years later, and under Michael Howard he became deputy party chairman.
In March 2004 he became a shadow local government minister and was again promoted in June to the shadow cabinet.
His interests include criminal justice and he helped to devise the scheme which has delivered thousands of CCTV cameras to towns across Britain.
A senior civil servant in the 1980s, Andrew Lansley became an active Tory after a spell as private secretary to Norman Tebbit.
In 1990 he was appointed head of the Conservative Research Department, acting as one of the key architects of the 1992 Tory election victory. He became an MP at the following election.
Mr Lansley was a key ally of William Hague and was responsible for planning the doomed 2001 Tory election campaign.
After Mr Hague's resignation, he backed Ken Clarke's leadership challenge despite his own Euroscepticism and argued the party needed to return to the centre ground.
He was one of the few Conservative MPs to oppose the Iraq war.
Under Michael Howard he has served as shadow health secretary.
When the Conservatives were in government, Tim Yeo was parliamentary aide to Douglas Hurd and then a junior minister in the Departments of Health and the Environment.
He was forced to resign as a minister in 1994 during John Major's "Back to Basics" crusade when he was revealed by the tabloids to have fathered a "love child" by an unmarried Conservative councillor.
As shadow agriculture minister under William Hague, Mr Yeo challenged the government over its handling of the foot-and-mouth crisis of 2001.
Under Michael Howard's leadership, he took up the "super-brief" of covering both health and education as shadow secretary for public services.
These roles were later split, leaving Mr Yeo as shadow secretary of state for both transport and environment, food & rural affairs.
He has now resigned from the shadow cabinet, to give himself more freedom to speak about the party's direction.
The ex-chancellor says he is not too old to run
Euro-friendly former home secretary Kenneth Clarke ran for the leadership in 2001 when opinion polls suggested he was the most popular Conservative politician with the British people.
He insists, at 64, he is not too old to throw his hat into the ring this time and has said he is waiting to see if the Tories are "leadable" before deciding whether to run.
His bid to take over as leader from John Major in 1997 failed, with the party electing William Hague.
Then in 2001 Mr Clarke was backed by the majority of Conservative MPs only to be rejected by the party membership in favour of Iain Duncan Smith.
The ex-chancellor's stumbling block has been his enthusiastic support for the European single currency and closer EU integration - something that stuck in the gullet of many grassroots Conservatives.
But he has indicated he believes the French and Dutch 'no' votes on the constitution will have helped his cause.
Eurosceptic former cabinet minister John Redwood challenged John Major for the leadership in 1995 and ran again in 1997.
Party grandee and shadow foreign secretary Michael Ancram ran for the leadership as a "unity candidate" following William Hague's resignation in 2001, but was the first to be eliminated, and transferred his support to Iain Duncan Smith.
William Hague has ruled out standing for the leadership again, no matter how many people within the party urge him to do so, but may take part in the debate over the party's future direction.
Since resigning as leader, he has written an acclaimed biography of William Pitt and forged a lucrative public speaking career. He remains a popular figure with the party's grassroots.
Theresa May was the first woman to become Conservative chairman and when she held that post she declared at party conference that Tories had to lose their "nasty" image and become more inclusive.
Now family and culture spokesman, she recently urged her party to become more women-friendly and be prepared to boost its number of female MPs with positive discrimination.
She is famous for her kitten-heel shoes.