BBC stars should be not be afraid of making risqué jokes or stirring creative controversy, the corporation’s Director-General will tell an audience of its best-known names, including Bruce Forsyth, John Humphreys and Jeremy Clarkson, at a special meeting tonight.

Mark Thompson intends to issue a rallying cry to the top talent after a series of morale-sapping controversies, including last week’s official rebuke for the comedian Frankie Boyle after he described Rebecca Adlington, the double Olympic gold medallist, as “somebody’s who’s looking at themselves in the back of a spoon” on Mock The Week.

Mr Thompson will say that the decision to invite the BNP to appear on Question Time, its airing of caustic political comedy The Thick of It, and the Iraq War drama Occupation shows that the licence-fee funded broadcaster has not lost its creative nerve.

The corporation has become increasingly rattled by a series of rows about a new “politically correct” model of editorial compliance in the wake of the Russell Brand/Jonathan Ross prank calls furore, which have left presenters and comedians increasingly demoralised.

Mr Boyle refused to apologise for the latest incident, telling Time Out magazine that “the number-one priority in TV comedy today is “don’t frighten the horses, and it’s probably number two and three as well. If you look at the scheduling nowadays, it’s all just celebrities meeting meerkats”.

An episode of This Week, the politics programme, was taken off the BBC’s iPlayer last month after Andrew Neil, the presenter, described Diane Abott, the black Labour MP, as a “chocolate hobnob” in an attempted joke. Fifteen viewers had complained about the remark. Mr Thompson is expected to tell his audience that “editorial guidelines are just guidelines”, and while he will ask for stars to “use their judgment” he will also promise that “there is freedom at the BBC to take risks” as he tries to enlist celebrity backing for the broadcaster he runs.

The string of rows led Channel 4’s head of programming, Julian Bellamy, to accuse the BBC of being trapped in a “a compliance spiral” that “threatens to bland out the medium to no one’s benefit” in a speech to the Royal Television Society last week.

He claimed that Channel 4, which tonight airs the death penalty drama The Execution of Gary Glitter, was the only broadcaster prepared to commission programmes that “break some form of mainstream convention or conformity”.

Channel 4’s claims, though, have antagonised the BBC’s top executives, who believe that there is no evidence that the broadcaster of Big Brother is a more successful risk-taking organisation.

“It would have been better if they had concentrated on giving a list of their own creative risk-taking rather than attacking us,” one BBC insider said.

One subject that Mr Thompson does not want to feature heavily in the discussion is pay. The BBC believes it is making enough progress on reducing top pay, with presenters such as Graham Norton agreeing to take salary cuts.

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