Boris Johnson is being considered as a possible Tory candidate to run for mayor of London, the BBC has learned.
Boris Johnson has had a colourful career as a Conservative MP
The Conservatives have been looking for someone to take on Ken Livingstone, who has held the post since 2000.
They had approached former BBC boss Greg Dyke, but he said he would only consider standing as an independent.
Mr Johnson, MP for Henley in Oxfordshire, said it was hard to see how he could do both jobs, but he was ruling nothing out.
'Urged to run'
He said: "Being mayor of London would be a fantastic job and anyone who loves London would want to consider the possibility very carefully.
"I want to stress that this idea did not come from David Cameron or from anyone in his office but I have, of course, been very struck by the number of people who have been urging me to run.
"In my case, there are huge obstacles - above all my commitment and responsibility to my constituency.
"It is hard to see how those difficulties could be overcome - but I am ruling nothing out."
Mr Johnson is one of the best-known Tory MPs thanks to his regular television appearances and frequent outspoken comments.
Former Conservative deputy PM Lord Heseltine did not appear to take the prospect too seriously, but said that in the past many people would not have taken seriously the idea of Ken Livingstone becoming London Mayor.
He told the BBC's The Daily Politics: "Boris is very well known, he has a big constituency, he's of a scale of character to match Livingstone."
The incumbent mayor, Mr Livingstone, is also known as an outspoken maverick whose refusal to toe the party line won him much popularity in London.
When he was not selected as the official Labour candidate for mayor in 2000, he left the party to run as an independent, winning by a large margin.
But he was later re-admitted to the Labour Party in January 2004 and was backed as the official Labour candidate, after Tony Blair said he had been persuaded by Mr Livingstone's record in office.
In May the Labour Party confirmed Mr Livingstone, the architect of London's congestion charge, would again be its candidate for the May 2008 elections.
The Conservatives have reportedly been turned down by several potential high-profile candidates including London Olympics supremo Lord Coe, radio presenter Nick Ferrari and former Met Police chief Lord Stevens.
In April they set out a five-month timetable to find a candidate - shortlisting applicants to go on to an "open primary" - with all Londoners on the electoral roll being allowed to vote.
The deadline for applications is 16 July, with a short list drawn up by 3 August.
Following a series of hustings, the primary will be held, closing on 26 September.
The winner will be announced at the Tory conference in September.
One of the Conservative front runners for the job, former think tank boss Nicholas Boles, has withdrawn from the race after revealing that he is fighting cancer.