Guardian political writer Hoggart, who also worked at The Spectator writing about television and wine, was revealed by the News of the World to have had an affair with Quinn at the same time she was conducting her three-year affair with Home Secretary Blunkett.
The paper revealed The Spectator publisher to have been carrying on with Hoggart behind the back of Blunkett and her husband, Conde Nast publisher Stephen Quinn.
Furthermore, the paper reported that married father of two Hoggart could also be the father of her Kimberly Quinn's unborn baby, which is due in February.
Hogart at first denied the story, calling it a "vile article" that was aimed at harming Quinn and that it was "just not true".
However, in a statement later issued to reporters, he said: "I would like to clarify reports yesterday relating to my friendship with Kimberly Quinn. Contrary to the impression I gave last night, we did have a sexual relationship, which started before her marriage, but the relationship became very infrequent indeed afterwards.
He denied there was any possibility that he could be "the father of either of her children".
One source told the News of the World that friends of the former minister said Blunkett suspected she was seeing Hoggart, but when confronted she denied the affair.
"David continues to be deeply hurt and every blow is a body blow. His family are so sad he got mixed up with someone so immoral and evil. It has got to the stage where Kimberly has no idea who the father is," one source told the paper.
Hoggart is reported to have been highly enamoured with Quinn and even wrote about her in The Guardian, referring to her as "the best-read non-academic I know".
Hoggart's involvement is all the more revealing because he is just the latest Spectator journalist to be involved in a sex scandal.
Earlier this year, the magazine's editor Boris Johnson's affair with deputy editor Petronella Wyatt was revealed.
Prior to that, Spectator writer Rod Liddle left his wife for the magazine's editorial assistant Alicia Munckton.
The goings-on at the Tory political magazine have earned it the nickname the 'Sextator'. Hoggart's affair with Quinn only helps cements the magazine's reputation.
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