TO THOUSANDS of Doctor Who fans she is Sarah Jane Smith, the confident and attractive companion who has given up travelling in his little blue box to battle aliens on Planet Earth will the help of a gang of schoolchildren.

But to the actors and staff of the Playhouse Theatre, some 40 years ago, she was just Elisabeth Sladen, the young assistant stage manager.

"It was a most fantastic company," recalls the Liverpool- born actress. "They were doing The Long and The Short and The Tall, which had sand all over the stage and you had to clear it every night because the actors would be rehearsing the next morning.

"I can remember when I was really young telling my parents I wouldn’t mind washing the stage and I bloody did. Absolutely, literally."

Her first acting role, if you could call it that, was a corpse. It was more difficult than it sounds – her husband-to-be, Brian Miller, made her giggle in the middle of the scene by whispering into her ear.

"Very naughty," she comments in her schoolmarm tones.

Sladen, now 61, stayed at the Playhouse for around a year, during which time it was closed for redevelopment and rehearsals moved to St Helens. When its assistant director moved to the Manchester Library Theatre, she and Miller agreed to go with him.

Her big TV break came in 1973, when she clinched the role of the Doctor’s assistant at an audition she assumed was for a much smaller part. She remained as Sarah Jane for three seasons, first with Jon Pertwee as the Third Doctor and then with Tom Baker as the Fourth.

She is one of the few characters to return to the show – in the 20th anniversary special The Five Doctors and more recently in the 2006 series starring David Tennant.

"I have different feelings for different doctors at different times in my life," reveals Sladen, who attended Liverpool‘s Elliot Clarke drama school. "Because I worked with Tom the most that is my ‘relationship doctor’, but I absolutely adore David, everyone does."

The middle-aged Sarah Jane was such a success that current writer Russell T Davies created her own show, The Sarah Jane Adventures.

"It was a different type of character than they’d had before. She had to be someone who had a mind of her own," says Sladen. "She was Earthbound, she wasn’t a space character, so you’re grounded in a reality as such, if you can say that.

"There was a certain point when Doctor Who seemed to catch the imagination, when it was with John and Tom, and I came in at that time which was fortunate for me."

Reprising such a well-loved role has been a true pleasure, she adds.