Jeremy Clarkson came out fighting against the BBC last night following ‘insider’ briefings which compared him to serial paedophile Jimmy Savile.

The Top Gear host instructed lawyers to demand an immediate retraction from the Corporation after the scurrilous allegations were spread by highly-placed BBC sources.

Clarkson is also seeking a full investigation into the identity of the BBC executive who leaked the groundless smear.

Jeremy Clarkson, pictured today, has instructed lawyers to demand an immediate retraction from the BBC following 'insider' briefings which compared him to serial paedophile Jimmy Savile

Friends said the Top Gear host was livid about being compared to Britain’s most notorious child molester

Clarkson is also seeking an investigation into the identity of the executive who leaked the groundless smear

Clarkson's friends say he believes it was a source connected to the office of former Labour minister James Purnell, now the BBC’s £295,000-a-year head of strategy. Above, the TV host leaving his London home today

His friends say he believes it was a source connected to the office of former Labour minister James Purnell, now the BBC’s £295,000-a-year head of strategy.

They said last night that while he was happy to cooperate with the inquiry into reports that he punched producer Oisin Tymon during a ‘fracas’ at a North Yorkshire hotel – a claim Clarkson denies – he is livid about being compared to Britain’s most notorious child molester.

Demanding an apology: Jeremy Clarkson this week

The BBC has denied Purnell had anything to do with the smear campaign. Sources have tried to pin the blame on another well-known senior executive.

Meanwhile, Clarkson and his co-hosts Richard Hammond and James May are exploring ways in which they can go ahead with a number of Top Gear Live arena shows, even though two TV programmes in this series have been pulled by the BBC’s Director of Television, Danny Cohen.

The three presenters are determined not to disappoint fans who have paid up to £95 for a ticket for the shows.

Clarkson, 54, was suspended by the BBC last week but is incandescent over ‘defamatory’ reports which quoted an unnamed ‘senior BBC source’ that drew parallels between him and Savile, who spent decades preying on under-age children.

According to the Mail on Sunday, a TV chief ‘who has been directly involved in the fallout from the incident’ said that politicians – including the Prime Minister – were turning a blind eye to Clarkson’s bad behaviour, in the same way as people once did with Savile.

‘If you look at what David Cameron says or what [former Culture and Media Secretary] Maria Miller says and you swap Clarkson for Savile, you get this: David Cameron is effectively saying that Savile’s a real talent, Maria Miller saying Savile will be Savile,’ the source was quoted as saying.

A BBC spokesman said last night: ‘To suggest that James Purnell is involved is categorically untrue and ridiculous.’

Earlier, Mr Cameron, who is a close friend of Clarkson, leapt to his defence, saying that his children would be heartbroken if Top Gear was taken off air permanently.

Yesterday, director-general Lord [Tony] Hall, insisted that the BBC still needs to determine the facts about Clarkson’s ‘fracas’ before making any decisions about his future.

‘The most important thing… is to gather the facts around you and not listen to all the speculation,’ he said at a media conference in London.

Clarkson, (right) Richard Hammond (centre) and James May (left) are deciding how they can go ahead with a number of Top Gear Live arena shows, even though two TV programmes in this series have been pulled

Lord Hall, Director-General of the BBC, last week described himself as a 'fan' of Top Gear presenter Clarkson

Asked whether he would take the money Clarkson makes for the BBC into account, he replied: ‘I will gather the facts of the case and make my decision based on a whole raft of things. But first let me get the facts in order.’

Clarkson was suspended last week after he allegedly punched producer Oisin Tymon (above)

BBC bosses will be aware of the problems they face without him. Top Gear averages around 5.5million viewers an episode, but a programme about the Red Arrows airing in the same slot on Sunday night attracted only 1.3million viewers.

Top Gear is sold in more than 200 countries, helping to pull in around £50million a year. The Corporation also makes money from a Top Gear magazine and Top Gear Live shows, staged in front of huge arena audiences. The next Top Gear Live events are due to take place in Norway this month, with four shows scheduled in front of a total audience of 20,000. They are now at risk of being cancelled.

Sources at the BBC’s commercial arm, BBC Worldwide, said it would decide what to do with the shows with executives at Brand Events, which has a 50 per cent stake in Top Gear Live.

However, Clarkson does not want fans to be let down, and is investigating ways of ditching the BBC banner and hosting the shows with May and Hammond in their own name.

Yesterday, it also emerged that Clarkson is due to host an episode of Have I Got News For You, when the topical panel show returns to BBC1 in May.

The plain-speaking host is understood to have been booked before the incident with Mr Tymon, and his slot has not been cancelled since the row erupted.

However, he is likely to stir up controversy if his appearance goes ahead as scheduled.

Jimmy Mulville, managing director of the independent company which makes the programme, said yesterday: ‘Maybe we will get the producer on so he can hit Jeremy Clarkson live on television.’

Jeremy Clarkson was spotted leaving his west London home today in a leather jacket and dark sunglasses