When the electorate sprinkles fairy dust on a vainglorious, thrusting politician and sends them to Parliament, we expect the expected. Once ensconced in his seat, our representative will be privy to all manner of temptation. The great and good might just succumb. Here are nine that did. And in the UK, it's nearly always sex that does it.
1. Keays To The Door
The scandal: In 1983 Cecil Parkinson, the 50-year-old Chairman of the Conservative Party "“ that slicked-backed golden boy of Tory politics "“ was found to be conducting an extra-marital affair with 34-year-old Sara Keays. And she was carrying his child.
The fallout: Keays told her story to the Times; Parkinson resigned his post. On New Year's Eve 1983, Keays gave birth to Flora.
Political suicide? Yes. Took the more junior posts of Energy Secretary and Transport Secretary; stood down at the 1992 Election.
2. Get Yer Kit On!
The scandal: In 1992, David Mellor, jut-toothed rising star in the Conservative Party and heritage minister, enjoyed a passionate affair with a little-known actress called Antonia de Sancha "“ she'd starred as a one-legged prostitute who shags the pizza boy in the straight-to-bin film The Pieman. During their conference it was alleged Mellor had romped in his Chelsea football kit.
The fallout: The Sun screamed "FROM TOE JOB TO NO JOB." De Sancha employed PR guru Max Clifford to milk her moment for all it was worth. Mellor posed for photos with his cuckolded wife Judith and their two boys. Britain cringed. Mellor resigned.
Political suicide? Yes. Remained MP for Putney until the 1997 General Election. Then appointed Chairman of the Government's Task Force on Football. He later left his wife. He currently presents If You Like That, You'll Like This on Classic FM.
3. Don't Badger The Witness
The scandal: In 1998, Ron Davies, the then Welsh Secretary, had "a moment of madness." He told police he had been robbed at knifepoint after meeting a stranger, one Donald Fearon, while taking a bracing stroll through a gay meeting place on a moonlit Clapham Common.
The fallout: The first person to resign from Blair's Cabinet. Later admitted he was bisexual.
Political suicide? Not yet. For that Davies needed to be caught in the bushes with a stranger at Tog Hill, a beauty spot near Bath. "I have actually been watching badgers since first thing this morning," said he. Quit Labour in 1994. Badgers kept silent.
4. Dead Reckoning
The fallout: Fooled everyone, including his wife, daughter mother, his party and the BBC. Bizarrely, returned to take up his seat. In 1976, the party demanded his resignation.
Political suicide? Deader than he'd ever been when merely pretending to be dead. Died for real in 1988. Apparently.
5. Spinning Out Of Control
The scandal: 9/11/2001. Thousands dead. World in shock. And Jo Moore, spin doctor to Transport Secretary Stephen Byers, sends out an email saying: "It's now a very good day to get out anything we want to bury." Classy.
The fallout: This was cynicism "“ or "spinicism" "“ at its very worst. Surely Byers had to sack her. But he didn't. This was the beginning of his end, and in May 2002 he bit the bullet "“ his resignation buried at a time when Westminster was in recess.
Political suicide? No. Byers was more a victim of the time than of his own behaviour. He remains an MP "“ albeit buried on the backbenches.
6. Tory Falls On His Sword
The scandal: Tory MP Jonathan Aitken appealed to "the simple sword of truth and the trusty shield of British fair play."
He'd been accused by the press of being involved in an arms deal with Prince Mohammed of Saudi Arabia. "Never! Not in this world!" said Aitken.
"If it falls to me to start a fight to cut out the cancer of bent and twisted journalism in our country with the simple sword of truth and the trusty shield of British fair play," he added, "so be it. I am ready for the fight. The fight against falsehood and those who peddle it. My fight begins today. Thank you and good afternoon."
Hurrah! He took the Guardian to court. He lost. Liar! He was jailed for 18 months after pleading guilty to perjury.
The fallout: Resigned from John Major's Cabinet before the trial "“ to spend more time with his lawyers. Lost his seat to Labour in 1997.
Political suicide? Yes. Aitken made noises about returning to parliament as a Tory MP, but he's not wanted any more.
7. A Family Man
He slept with the wife and daughter of South African judge James Harkness. Clark suggested he should be "horse-whipped" for all his extra-marital affairs.
The fallout: The man whose diary was turned into a six-part series for BBC Four "“ the castle-dweller who thought police following his speeding car were his escort "“ was never going to be done down so easily. The affair produced a great anecdote. And there were plenty of envious glances from his colleagues.
Political suicide? Sure, he quit politics at the 1992 election, but missed it greatly. Died while MP for Kensington and Chelsea.
8. Bottoms Up
The scandal: In 1981, ginger Labour MP Allan Roberts visited Berlin's Buddy Club. A witness claims Allan was approached by a man clad in an SS uniform. "Name," he demanded. "Allan," said Allan. "Nein," said the German. "It is Rover." He then attached a lead to Allen's studded dog collar and whipped him before a baying crowd.
The fallout: He denied ever being into bondage. He said he'd been drunk, fallen over and injured himself.
Political suicide? No. Received a massive vote of confidence from his local party members. When he died in 1990, he had a spanking good majority of over 24,000.
9. The Greatest
The scandal: The LibDems might not be able to point to much scandal, but they can boast of Horatio Bottomley, a gifted cheat of flamboyant character, widely regarded by historians as the most corrupt MP of all time. He was, in 1922, jailed for seven years for various frauds.
The fallout: Persuaded the prosecution to allow him to break each day at 11:30 so that he could drink a bottle of champagne. Tried a comeback. But failed.
Political suicide? Yes. Remained in the public eye, touring the Empire lecturing.
Paul Sorene is the Anorak. He survives on donations and the tolerance of Old Mr Anorak, his patron. Paul is hawked out to various media outlets whenever OMA is low on supplies. Paul has written for numerous news organs, and will be filing occasional reports from the UK for mental_floss.