He was an old-fashioned charmer, opening doors and all the rest of it, making you feel like a lady. So our relationship was inevitable

Barbara Windsor on Sid James

The inside story of that relationship, from its light-hearted, flirtatious beginnings to its unhappy end, has been recreated in the ITV comic film Cor Blimey!

Geoffrey Hutchings plays James and Samantha Spiro is Windsor in the film, which also recreates some of Carry On's most memorable "slap-and-tickle" scenes.

It also features a special cameo performance by Barbara Windsor herself, who was an advisor to the cast.

Cor Blimey! was the idea of writer and director Terry Johnson and based on his award-winning play Cleo, Camping, Emmanuelle and Dick, in which Spiro also starred.

Johnson says he is fascinated with looking into, and recreating, Carry On's sensitive past.

Hawtrey (Hugh Walters) had a troubled private life

"One of the ironies is the abject misery most comedians seem to go through towards the end of their lives.

"Another surrounds the comic joys of sex as portrayed in the Carry Ons versus the rather unfunny complications we truly find ourselves in."

Relentless pursuit

In the case of James and Windsor, their difficulties lasted more than a decade and began the day Windsor first walked on the set in 1964.

As Cor Blimey! shows, the married and middle-aged James was immediately stung by the attributes of the busty blonde in her 20s.

He began a relentless pursuit of the young actress who proved to be no pushover. But, despite her marriage to Ronnie Knight, Windsor, finally gave in to the actor.

"I cared deeply for him," recalls Windsor. "I didn't at first, he was just my leading man and I used to push him off.

The real Windsor (right) was an advisor on the film

"But he was an old-fashioned charmer, opening doors and all the rest of it, making you feel like a lady. So our relationship was inevitable."

But as the years went on it was also doomed as it became hopelessly entangled in their screen personas.

In addition, James' ill health and the pressures of working as part of Britain's top comedy group took their toll.

The affair that began in laughter more than 10 years earlier came to a turbulent end.

Moving role

Windsor found watching her Carry On days played out in front of her both funny and very moving.

Samantha Spiro, who plays Windsor, says she found the experience emotional as well.

"I felt a sense of responsibility playing Barbara but she has been unbelievably generous.

"I can't imagine there are many actresses alive now that you would feel so comfortable playing," she explains.

Cor Blimey! recreates the famous bikini scene

One aspect Spiro felt particularly nervous about was the notorious breast-baring scene from Carry On Camping when Windsor's bikini top flies off.

"There's a certain generation of men for whom that scene sticks in their memory as a point of growing up.

"We discovered that it was attached to a piece of fishing line to yank it off at just the right moment.

"But one night on stage it flew off too soon and it was a couple of seconds before I realised - I've never been so embarrassed."

Inevitably, the scene prompts Sid James to let out one of his notorious guttural laughs.

Rare characters

It was this particular characteristic that gave Geoffrey Hutchings the key to playing the craggy-faced comic, who died in 1976.

"Once I got the laugh, I had a way in but it wasn't easy because Sid was quite a quiet man in real life and there isn't much archive material of him as himself," says Hutchings.

Adam Godley plays the outrageous Williams

"But having played him, I wish I had met him. He was a rare character and I'll always have a fondness for him."

Among the other characters who feature largely in Cor Blimey! is the outrageous Kenneth Williams, who provides Windsor with a friendly ear.

He is played by Adam Godley who explains why he revelled in the part.

"It was great to have those costumes for the film. I even got to wear a toga which Kenneth talks about in his diaries about rather fancying himself in.

"He wouldn't take it off, wore nothing underneath and went around flashing at everyone on set."

Godley is particularly proud of his role in the film.

"The tension of the relationship between Sid, Barbara and Kenneth makes a really good brew.

"There's the fondness between Kenneth and Barbara, the relationship between Sid and Barbara and the jealousy and antipathy between Sid and Kenneth. It's absolute gold-dust."

Cor Blimey! is shown on ITV on Monday 24 April at 2100 BST.