The last time Major took the moral high ground a lot of his colleagues fell off

Claiming the moral high ground from Tony Blair and New Labour is a high-risk gamble for John Major.

The last time Mr Major attempted to take the high ground, with "back to basics", the Government was hit by a series of sex scandals and other controversies. Ministers and MPs resigned on what seemed like a monthly basis.

David Mellor was the first of the Tory ministers to resign in September 1992 after his affair with a model. It came before Mr Major's speech, but it continued to reverberate and may well have influenced the decision to reaffirm family values.

But the strategy - the brain child of Sarah Hogg, then head of the Downing Street policy unit and promulgated at the Tory conference in 1993 - opened the Tories to the charge of hypocrisy.

Steve Norris admitted to having an affair at the same conference. He survived the storm, but never got the Cabinet promotion which many felt he deserved.

The year that followed plunged the Conservative Party into a series of scandals like a long-running Whitehall farce, which turned into a tragedy.

Within three months, Tim Yeo, an Environment minister, had resigned after admitting having fathered an illegitimate child. Mr Yeo's departure in January heralded a parade of ministers leaving the Government.

Stephen Milligan, a rising star on the Tory backbenches, died in a bizarre sex act which went wrong. The shock of Mr Milligan's death was followed by the allegations over David Ashby sharing a bed with another man, which led to a celebrated libel action.

Lord Caithness resigned after his wife shot herself, and the toll continued as Hartley Booth, once a trusted adviser of Margaret Thatcher, admitted having an affair with his researcher.

Michael Brown, a Government whip, resigned over allegations of a gay affair and Alan Clark, a former minister who had left the Commons in 1992, described in his diaries a series of sexual adventures which surpassed the fiction writers.

Robert Hughes, a close ally of the Prime Minister, resigned after admitting an affair with a constituent. This year, the Prime Minister's patience with ministers was exhausted. When Rod Richards was accused of an affair, he was ordered to resign within 24 hours.

The sex scandals were overtaken by other embarrassments for the Government, which led to the Prime Minister establishing the Nolan Committee on Standards in Public Life in an attempt to clean up the Tories' public image.

Jonathan Aitken, a Defence minister, resigned in 1994 to fight allegations of accepting hospitality at the Ritz in Paris. Neil Hamilton, another minister, resigned after a similar controversy and his libel action against the Guardian will go ahead during next month's Conservative Party conference.

The allegations were heightened by the disclosure that two Tory MPs appeared to have been prepared to table Commons questions in return for cash.

Mr Major, unlike Baroness Thatcher, has avoided using the Bible as his text for his political beliefs. He launched his renewed campaign on morality as a reaction to the Christian Socialism of Tony Blair. It could become known as Christian Capitalism, unless it backfires on Mr Major.