The 55-second video did not cost anything, says Downing Street
Downing Street has been accused of wasting taxpayers' money after making a jokey video in response to a petition for Jeremy Clarkson to be made PM.
The 55-second clip, on Number 10's You Tube site, was created after nearly 50,000 people backed a call for the Top Gear presenter to be prime minister.
No 10 said the clip had been created by a member of staff who had a "spare half hour" and had not cost any extra cash.
But the Tories said it showed the government had lost touch with reality.
The clip thanks everyone who signed the online petition and says officials have "thought long and hard" about it.
The camera then pans up the famous Downing Street stairs, showing photographs of former prime ministers, before focusing on an image of Mr Clarkson.
The final message reads: "But on second thoughts... maybe not."
A Conservative Party spokesman said: "While the British public is having to tighten its belts, the government is spending taxpayers' money on a completely frivolous project."
"This shows how detached the Labour Party has become from the concerns of the British people."
But a Downing Street spokesman stressed the film was a joke, and had not cost any extra money to make. "It was a pretty light-hearted petition, so we gave it a light-hearted answer.
"A member of staff put it together in a spare half-hour."
The Number 10 petition site has generated much controversy since its launch in November 2006 - with 1.8 million e-mails calling for road pricing to be scrapped.
There have also been several jokey petitions, including one calling for Spandau Ballet's Gold to be the new national anthem.
The Jeremy Clarkson for PM petition is now closed but more than 100,000 people have joined Facebook group calling for the outspoken presenter to be installed in Downing Street.
Visitors to the Downing St website are invited to view the Clarkson clip
Mr Clarkson - whose views on motoring and the environment have earned him a cult following - recently confessed he would be a "rubbish" prime minister, adding that the government should be in charge of "building park benches and nothing else".
A new Downing Street petition urging the government not to bestow a knighthood on Mr Clarkson "until he has done something truly worthwhile and of benefit to the UK" has received so far 34 signatures.
Downing Street last week relaunched its main website to boost the amount of video content.
But the revamp was hit by a series of glitches - including the accidental publication of a "test" message accusing former No 10 aide Benjamin Wegg Prosser of being a "prat".
The bizarre message, dated Friday, 4 May 2007 says: "PM backs Benjy in 'prat' row. The prime minister has backed his special adviser, saying he's 'a prat, but not the prat'.
It is thought to refer to press reports at the time in which a government minister is reported to have called the person who created the Downing Street petition site a "prat".
The link to "BWP Home" from the test page brought up an image of actor Daniel Radcliffe playing Harry Potter - widely held to resemble Mr Wegg Prosser.
A No 10 spokesman said the pages had been removed as soon as the mistake was spotted.
"These are test pages that were created several years ago and were carried over to the new Downing Street website in error and have now been removed," he added.