BBC1 presents 'The Truth' and nothing like the truth about Jeffrey Archer

It is Jeffrey Archer's life story – but not even as the criminal fantasist himself would have dared to imagine it.

In BBC1's new satirical drama about the disgraced Tory peer, Archer weds the fragrant Mary, loses a fortune in a financial scandal and writes a bestselling blockbuster.

So far, so accurate. But the writer Guy Jenkin, creator of the television sitcom Drop the Dead Donkey, describes a fictitious Archer whose capacity to embellish the truth surpasses even the original. To the rousing accompaniment of "Land of Hope and Glory", Archer, played by Damian Lewis, boasts of his affairs with not only Margaret Thatcher, but with Diana, Princess of Wales.

He is also revealed as a hero of the Iranian embassy siege and the 1984 Brighton bombing and he generously takes the blame over the scandal with the prostitute Monica Coghlan to save the Government. The viewer is then taken into a future where Archer has left prison, helped England to win the 2006 World Cup and clambered back on to the greasy pole to success.

Jeffrey Archer, The Truth, to be screened on Sunday 1 December, takes the form of conversations with a young writer whom Archer has employed to write his unauthorised biography, because, he admits, "if I were the author, people might not believe it."

Lewis, who starred in The Forsyte Saga and Band of Brothers, and was a contemporary of Archer's son, James, at Eton, described Archer yesterday as "not unattractive". He said: "I think it's an affectionate portrait, but premised on a massive in-joke – that you suspect Archer is not the humble victim of circumstance that he's portrayed as here."

Archer himself is obviously not convinced. Jane Tranter, the BBC's controller of drama commissioning, said a letter had been received about 16 months ago from a producer on behalf of the jailed writer.

It offered the BBC the alternative of a television version of his play, The Accused, in which the audience votes on the guilt or innocence of the character played by Archer. Archer would be out of jail next year, the letter said, and could revive the part he played on stage. The BBC declined the offer.

But by pressing ahead, the BBC could face storms of protest. The Brighton bombing is still a sensitive subject and Baroness Thatcher is unlikely to be amused by the depiction of her fictional affair, even if she is portrayed by Greta Scacchi. Diana's friendship with Dodi Fayed is portrayed as a cover-up for a relationship with Archer.

Jenkin played down the likelihood of causing offence. "The whole piece is a joke about Jeffrey Archer and his 'tendency to inaccurate precis', in the words of Mary Archer," he said. Lorraine Heggessey, the BBC1 controller, said the best satire had to be risky.