Alistair Beaton, whose play A Very Social Secretary will be screened in October, insisted he has written a comic version of serious events in which the public has a legitimate interest.
Channel 4 stood by its decision to screen the play, despite a warning letter from Mr Blunkett's lawyer. The Secretary of State for Work and Pensions is angry about a scene in the play that refers to his two-year-old son by Kimberly Quinn, which he regards as an unjustified intrusion into the child's privacy.
"The child plays a very minor role," Mr Beaton said yesterday. "The drama is really about politics and life and sex - about Blunkett's relationship ... with Tony Blair and ... with Kimberly Quinn. It's about Blunkett's public life and, to some extent, about his private life. The two overlap, which I suppose is inevitable in a politician.
"Although it deals with serious issues, it's a comedy. I think people will find it's quite funny."
A spokesman for Channel 4 said the drama was still being edited. "We are confident in what we are going to be showing. The drama is very much about the affair ... It doesn't go beyond the relationship between Blunkett and Quinn."
The row has brought welcome publicity for More4, Channel 4's new service, available only to digital viewers - and unwelcome publicity for Mr Blunkett, who would like his disastrous affair with the former publisher of The Spectator magazine to be forgotten.
The affair has already inspired a musical and a stage play. Now comes the television comedy, to be broadcast on 10 October, starring Bernard Hill as Mr Blunkett and Robert Lindsay as Tony Blair.
Alastair Campbell has also been written into the script, although his role in the Blunkett affair was minimal, as he left Downing Street before it became public. This may be because Mr Beaton has a soft spot for his near namesake, having written a successful West End stage play, Feelgood, featuring a hyperactive Downing Street press secretary.
One of the comic themes is the contrast between Mr Blunkett's image as a down-to-earth man from a working-class background and the social life he shared with his rich American mistress. The Prime Minister values the image as an electoral asset, and is thunderstruck to discover that Mr Blunkett has a sex life.
In one scene, Mr Blair is warned by an adviser of the possibility that Mr Blunkett will be given a "bloody nose" by the House of Lords, but he brushes this off with a confident declaration: "It's a very robust nose. It's a man of the people's nose." The scene then cuts to a shot of Mr Blunkett's nose, deep in a glass of wine. "It's corked!" he exclaims.
Mr Blunkett is on holiday. A spokesman said: "He takes matters relating to the privacy of his son very seriously."Reuse content