Quinn 'had second affair while she was still seeing Blunkett'

The Kimberly Quinn affair was threatening to engulf a second Westminster figure last night after the News of the World claimed that she was conducting two affairs at once.

The newspaper named Simon Hoggart, parliamentary sketch writer for The Guardian, as Mrs Quinn's second lover. Mr Hoggart, however, vigorously denied the claims. He said: "This morning I got a phone call from the News of the World saying you have had an affair. I said I have not. I said if you have any evidence fax it to me. I heard nothing. They didn't ring, they didn't fax this stuff."

He continued: "We are good friends and that is the extent of it. Somebody who hates her very much... is trying to blacken her name. We were good friends. She probably said nice things about me, 'He is witty and amusing, and a good writer'."

The revelation, if true, would cast further doubt over the paternity of the American publisher's second child, due in February. While Mr Blunkett is reported to have challenged Mrs Quinn over her friendship with Mr Hoggart, Mrs Quinn, denied that she was cheating on the former Home Secretary, according to the paper.

The 58-year-old journalist, who is married, is the wine correspondent and television critic for The Spectator, the magazine of which Mrs Quinn is the publisher.

Mrs Quinn, heavily pregnant with a second child, only left hospital Friday night after treatment for complications her husband Stephen says have been brought on by the stress. The couple left their Mayfair home before the latest reports surfaced.

Stephen Quinn, 60, a Condé Nast executive, promised to stand by his wife after the news of her three-year affair with Mr Blunkett was revealed in August.