While the anti-drugs slogan Just Say No is usually credited to former US first lady Nancy Reagan, for people who were children in the 1980s the phrase remains indelibly associated with one fictional character.

The sight of Samuel Zammo Mcguire, from soapy state school drama Grange Hill, slumped in the backroom of an amusement arcade surrounded by drug paraphernalia, was a ground-breaking representation of the perils of heroin.

His slide into addiction gripped followers of the series and led to a charity single "Just Say No", which climbed to number two in the charts in 1986.

Depicting the decline of the popular cheeky chappy character into a desperate thief who steals a valuable decanter from his own mother to fund his habit was daring for children's TV at the time.

All of which makes the news that the actor who created Zammo, Lee MacDonald, is to join the cast of Eastenders that bit more noteworthy.

Some 32 years since he gave up the role of Zammo, MacDonald, now aged 50 is to play a London bus driver called Terry who goes head to head with the Mick Carter, the landlord of the Queen Vic, in a radio competition.

Concert tickets are up for grabs, but Terry stands in the way of Danny Dyer's Mick, who intends to bag the prize as a surprise for his wife Linda.

MacDonald is far from the first Grange Hill star to graduate to the BBC's flagship soap opera. At least four former alumni of the TV comprehensive have made the leap to Walford.

Susan Tully, who played sulky teen Suzanne Ross had a lengthy stay in Albert Square, as Michelle Fowler, while one of Grange Hill's most popular characters, Tucker Jenkins was the breakthrough role for Todd Carty who later played Michelle's brother Mark.

Singer songwriter Michelle Gayle was a schoolgirl with musical ambitions in Grange Hill before going on to play Hattie Tavernier in Eastenders for three years, while Sean McGuire - Tegs Ratcliffe in Grange Hill - was also Aidan Brosnan, who started out as a promising footballer for Walford FC but ended up a homeless and suicidal squatter.

MacDonald said he was delighted to be making a TV comeback, albeit with only two episodes guaranteed at present. "I am absolutely chuffed to bits and so excited to be briefly joining the cast of EastEnders," he said. "I can't say too much yet - but watch this space! Top banana!"

At the height of the Zammo storyline, and on the back of the Just Say No single, MacDonald and several other members of the cast were invited to the White House to meet Nancy Reagan. A popular but probably apocryphal tale has it that several of them were stoned when they had their audience with the first lady.

This story seems to have arisen as a result of some vainglorious boasting indulged in by Erkan Mustafa, who played Roland in the drama, in the presence of a tabloid reporter. Both Mustafa and MacDonald have since debunked the claim, pointing out the unlikeliness of dodging White House security for long enough to smoke any illicit substances.

After five years in the Grange Hill cast, MacDonald left acting behind in an attempt to become a professional boxer, but his dreams were thwarted when he was injured in a car crash.

Since then he has run a locksmith business, while making occasional TV appearances in programmes including The Bill, Birds Of A Feather and A Midsummer Night's Dream.

He has also made appearances as himself in Pointless Celebrities, Cirque de Celebrité and Celebrity Scissorhands.

While the Zammo storyline and the charity single helped raise the profile of drugs, the 'Just Say No' approach has fallen from favour.

Last October, drug and alcohol charity Addaction Scotland cautioned against returning to that message. Gareth Palmer, project manager at Addaction Scotland, said it didn't work and talking to young people was more constructive.

“Telling a teenager to 'just say no’ isn’t helpful and is often counterproductive. Our advice is start the chat, keep talking, listen well and don’t turn it into a big thing," he said.