Piers Merchant: Tory MP whose career ended when he was caught having an affair with a teenage Soho nightclub hostess

In his relatively short political career, the one-time Conservative MP Piers Merchant attracted an inordinate amount of publicity which was exceptionally damaging to both himself and his party.

He was the object of not one but two tabloid newspaper "stings" in 1997 which pictured him in activities such as an "open-air sex romp" with a 17-year-old Soho nightclub hostess.

He survived the first exposé but had to resign from Parliament when he was engulfed by the second, in which he was caught red-handed: secretly-filmed footage showed him in bed with the hostess. The headline "Sleaze Merchant" proved irresistible to several newspapers. The wider significance of his extra-marital activities was that, hitting the papers as they did at the time of the 1997 general election, they added to the tide of sleaze which helped propel John Major from Downing Street.

Piers Rolf Garfield Merchant had a background in journalism and public relations. Born in 1951, he attended Nottingham High School and studied law and politics at Durham University, where he was active in Conservative student politics. He worked at The Journal in Newcastle, first as a reporter and later news editor, before switching to PR. He became Tory MP for a Newcastle seat in 1983 but lost it four years later, before returning to the Commons in 1992 as MP for Beckenham in Kent. An avowed Thatcherite, he made only modest progress at Westminster, serving as parliamentary private secretary to the social security secretary Peter Lilley.

He really came to public and political notice, however, when The Sun revealed he had been kissing and cuddling in a public park with Anna Cox, a teenage Soho nightclub hostess. A Sun photographer who had been lurking in the undergrowth had the pictures to prove it. It was claimed that The Sun, which at that point had moved to support Labour, was eager to damage the Tories through such stories.

Mustering all his journalistic and PR skills, he decided on outright denial. "Anna is a dear friend of mine, but there is no question of us having an affair," he maintained. "I have never made love to her. That may well be me kissing her in the picture, but I see nothing wrong with that. I am sure my wife will not be the slightest bit concerned."

With his wife, Helen, loyally standing by him, his assertions convinced the voters of Beckenham to allow him to hold his seat, in an election which saw so many of his Tory colleagues losing theirs. But the media had not finished with him. The Sunday Mirror was on his case, correctly believing that he was indeed having an affair with Cox, and a "love-nest" used by the pair was fitted with secret cameras. Six months after the election the paper went to press. Merchant's first instinct was to deny everything, and indeed, initially to threaten legal proceedings: but that was before the full extent of the Sunday Mirror's evidence became apparent.

Merchant would later recall calling his wife from a mobile telephone on a crowded train to confess that – this time – he had indeed been having an affair. "She was furious, of course," he said. "She called me a complete idiot and asked, 'How could you be so stupid?'"

Even after the most conclusive pictures were printed in a six-page spread, Merchant sought to brazen it out. A statement in the name of himself, his wife and his mistress rejected "scurrilous allegations," describing Miss Cox as a family friend. In a bizarre episode the three gathered in the Merchant family home while it was besieged by the media. At one stage Helen Merchant appeared on the doorstep with Cox to emphasise the "family friend" characterisation.

Later, clearly agitated by the media attention, Miss Cox was escorted out of the house by police and paramedics. Under pressure from within the Tory party, Merchant bowed to the inevitable and quit the Commons, returning to the PR business.

In later interviews he admitted that, second time round, there was an affair but insisted that it had not started at the time The Sun ran its story. He conceded, however, that he had been economical with the truth.

"As the story was breaking I made a statement which was deliberately misleading," he said. "To counter the allegations, I issued a statement saying categorically: 'Piers Merchant and Anna Cox are not having an affair.' Strictly speaking, because of the tense, that was true. We were not having an affair. We were sitting at home with my wife and family. I admit it was deceptive. I was trying to be too clever and I regret that."

In 2002 he expanded on this: "The backdrop was a highly charged political one – the election starting and the whole sleaze background. In terms of the facts, the basis of the Sun story in March was not correct. The second time around, to everyone's amusement and surprise, I was having an affair, it was correct."

According to his version, the affair started only after he contacted Cox in an attempt to discover how he had been "set up", and they began work on a book on press intrusion. He maintained, in other words, that he had not been having an affair with the teenager until after The Sun claimed he was.

He also said that "pressure and duplicity" had been used to urge him to stand down before the election. This was hardly a revelation, since Michael Heseltine had gone on the BBC's Today programme to urge him "to consider very carefully the consequences of what has happened."

He later attempted a political comeback, joining the UK Independence Party, acting for a time as its general secretary and standing unsuccessfully in the 2004 European election. At one point it is said he received a note from the UKIP personality Robert Kilroy-Silk, who was anxious to keep a discreet distance from him. "Please do not stand within 10 yards of me," the note specified, "because I'm sure you'll understand that I do not wish to be photographed alongside you."

He is survived by his wife Helen and two children.

Piers Rolf Garfield Merchant, journalist, PR consultant and politician: born 2 January 1951; married 1977 Helen Burrluck (one son, one daughter); died 21 September 2009.