Christine Keeler doesn't like me, says former friend Mandy Rice-Davies - Telegraph.co.uk

Keeler, meanwhile, has kept her distance.

"Andrew wrote to her asking if she wanted to be involved but I think she was busy with a project of her own," Rice-Davies said.

The show, which opens in the West End later this year, charts the rise and fall from grace of Ward, friend to film stars, spies, models, government ministers and aristocrats.

It was he who introduced Keeler to John Profumo, the secretary of state for war in Harold Macmillan's Conservative government.

Profumo began a sexual relationship with the showgirl, who was also said to be sleeping with Yevgeni Ivanov, the senior naval attaché at the Soviet Embassy.

The affair, and Profumo's denial of it to Parliament, precipitated his downfall.

Rice-Davies suggested that his big mistake was in lying about it.

"That was the point that festered," she said. "Most of the press knew that Christine had been having this affair with Profumo.

"There was this festering until the question was asked in Parliament and when he denied it there was kind of a storm close to fury.

"Had he actually stood up and told the truth he would probably have gone to the back benches, maybe."

Today's politicians could "absolutely" learn a lesson from the affair, she added.

"If a rumour starts going around, [they should] just stand up and say 'mea culpa'," she said.

"Whenever in the Whitehall village someone is accused of something and denies it, it's automatically assumed they have done it."

An instant confession would limit any scandal, she argued.

In June 1963, Ward was charged with living off the "immoral earnings" of Keeler and Rice-Davies but took an overdose of pills just before the end of his trial and died shortly after he was found guilty.

Lloyd Webber said he had become "intrigued" by Ward after reading books about the trial.

"Ward became the scapegoat for a number of things," he said.

"It was the time and mood to get the Macmillan government because two journalists had been to prison for not revealing their sources on something, and at the same time police were instructed to get something on Ward and turn him into an apology for what had gone on."

The musical, directed by Richard Eyre, depicts the sexual permissiveness of London's elite at the time, and includes references to sadomasochism.

Rice-Davies suggested the early 1960s were far less permissive than today's society, however.

"The promiscuity in those days – there were good girls and bad girls," she said. "The good girls didn't have any sex at all and the bad girls had a bit."

Stephen Ward opens in December at the Aldwych Theatre in London.