The BBC's Joshua Rozenberg: A self-confessed liar

The former Conservative MP was sentenced on Tuesday to 18 months in prison for perjury and perverting the course of justice.

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He admitted both charges earlier in the year, following the collapse of his libel case against The Guardian and World in Action.

The judge told Aitken, 56, he had spun a "web of deceit", from which he had not been prepared to escape by telling the truth. Aitken was later taken away to begin his sentence at Belmarsh jail near Woolwich, south London.

Aitken turned to God in his hour of need

But the former minister has now spoken of his "eternal shame" at asking his wife and daughter to lie about his stay at the Paris Ritz.

His confession is published for the first time in an abridged version on the Website of the Catholic weekly newspaper, The Tablet. It was originally a speech which he gave last August to the CS Lewis Foundation and the Prison Fellowship Trust.

Despite her father's contrition, his daugher, Victoria, 18, has hit out at the prison sentence, saying it is too harsh. She told The Daily Telegraph her father's plight was similar to US President Bill Clinton's.

Victoria Aitken says her father is a "good man, perhaps even a great man"

"He told a lie under oath too, but he's still president ... while my father is now in jail," she said.

Aitken forbade the publication of his confession until now, in case it was thought that he was trying to win sympathy from the judge.

He explains how he came to lie during his failed libel case, with pride, "the deadliest of sins", at the root of the problem.

"The political graveyards are littered with the long-forgotten corpses of ex-future prime ministers, so any such label should have made a wise man humble," he said.

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"In fact, I did quite the reverse. I took myself far to seriously, especially when I was made a target of a campaign by The Guardian."

Aitken says the newspaper "made a number of allegations against me, some of which were true, some of which were untrue".

He also refers to his notorious press conference performance when, launching the libel action, he vowed to "cut out the cancer of bent and twisted journalism with the simple sword of truth".

He describes the soundbite as "insensitive words of pride which came back to haunt me", and says of the libel case: "In order to win it ... I told a lie.

Religious retreats

"It was a lie about who paid a �1,500 hotel bill of mine in the Ritz Hotel in Paris while I had been a government minister."

Aitken said his "whole life was shattered" within 24 hours of the collapse of the trial. Since then, he has attended religious retreats and completed the Christian introductory Alpha course at the Holy Trinity Brompton church in west London.

The speech will be printed in the next edition of The Tablet on 12 June.