Thanks to these iconic Sixties and Seventies children's programmes, Cant has attained the sort of cred usually reserved for here-today-gone-tomorrow boy bands. At Hull University there is the inevitable Brian Cant Appreciation Society - which, it is claimed, boasts 200 members. No doubt he'll soon be elected president of the Junior Common Room at some waggish Oxbridge college. James Tillitt, the producer/ director of Cant's latest venture, playing the Vicar in Michael Bogdanov's adaptation of The Canterbury Tales, comments that "Brian is a cult figure to those in their late twenties and thirties. In Oxford, many students came up and asked for his autograph." (Play School even numbered Eric Morecambe among its fans. He used to record Morecambe and Wise in an adjoining studio and visit the Play School set during breaks. Cant says Morecambe was "distraught" when he discovered that Big Ted had been stolen one lunchtime.)
But more importantly for Cant, those youngsters who first lapped up his children's programmes are now adults with jobs to offer him. "All of the Playaway generation are now coming through to employ me," Cant laughs. "I want them all to work in commercials, television and films. They're rooting for me now because Play School is something missing from their lives."
Like Gary Glitter, Cant has relished a second-wind career in commercials - including a send-up of Camberwick Green for a brand of bread in which, Cant recalls, "a man ate some bread that wasn't baked by Windy Miller and his head fell off." Perhaps the easiest ad he ever had to do, though, was one for a beer which depicted a raging bush fire. All that was required of Cant was to call out the fire brigade from Trumpton - "Pugh, Pugh, Barney McGrew, Cuthbert, Dibble, Grub" - the mantra that everybody from the ages of four to 40 has learnt at their mother's knee. "I was in and out of that ad in two minutes," Cant reveals. "It was lovely."
Cant has also landed parts in the theatre courtesy of a past that involved talking to teddy bears and dolls. "I did the Alec Guinness part [Dr Wickstead] in Alan Bennett's Habeas Corpus at the Theatr Clwyd. I asked the director why she'd cast me - I can always think of someone else who could do a part better than me. She said she'd seen something through the lens of Playaway that she liked about me." She surely meant an unremitting liveliness.
Nibbling on a tuna sandwich, Cant is talking to me in the lunch break between rehearsals of The Canterbury Tales in the library at the American Church on Tottenham Court Road in central London. While a fellow cast member hammers out Oasis's "Wonderwall" on a piano in the background, Cant lounges on a sofa in front of a bookcase containing The Apostle's Creed for Everyman by William Barclay, Modern Theology by Karl Barth and In the Footsteps of Moses by Moshe Pearlman. (Well, he is playing the Vicar.)
He has thinning hair these days, spectacles hanging on a string round his neck, and a staid blue jumper and cords rather than the yellow dungarees beloved of children's presenters the world over. He may be a (youthful) 62 years old now, but he is still recognisably the man who enlivened our childhood through his menage with Humpty and Jemima and Hamble.
Cant recalls with particular fondness the early days of Play School - which he launched in 1961 in the company of Emma Thompson's parents, Phyllida Law and Eric Thompson. "When it started," he recollects, "it didn't have any jokes, but gradually we put in silly rhymes and sketches and a lot of music-hall stuff - lovely old songs like 'My Brother Sylvestre' - and it became much zanier. We could go into the realms of fantasy, and it worked because the people watching would enter into our mad world."
Playaway got out and about a bit more. Cant remembers playing King Canute on an Ayrshire beach. "I wore a cloak and crown on top of a wetsuit and I needed it. When they built the throne, they hadn't reckoned with the force of the waves and they kept taking me out to sea. We had to do a lot of takes, and the director kept plying me with rum. By the end, I felt a bit wobbly but very warm." Did he ever feel that these stunts were the teeniest bit undignified for a grown man? "No," smiles the father of three children under 10. "I'm all for that sort of thing."
After the lunch break, he dons a dog collar, a battered Panama hat and half-moon spectacles to play the bumbling vicar trying in vain to stop too many obscenities from spurting out of the tales being re-enacted on his front lawn. He has most difficulty suppressing the bawdy interpolations of the Miller (Brian Glover, in typically rumbustious form.) During the Wife of Bath's tale, a raucous woman chants: "Her passion, you'll have to sate,/ Or she'll be forced to mastur..." "Her feelings," the Vicar interrupts, hastily. Cant says he enjoys the part because "the Vicar is a bit of a nincompoop. He's slightly pompous, and there's nothing funnier than pomposity being attacked." He is obviously having a ball in a romp that one critic described as "Carry On Chaucer".
Tillitt looks on at Cant's controlled anarchy and smiles like an indulgent parent. "He's the ideal Vicar," he observes. "The whole piece is meant to look as if it's ad-libbed. Things go wrong deliberately, but Brian's skill is being able to make it look as if it really has gone wrong and the whole evening is falling down around him. He has great warmth, and his ability to communicate with an audience is wonderful. His comic timing is excellent. He knows what to say and when to say it. He's got a very quick mind, and when things do genuinely go wrong he's very quick to get in and fix them." All those years breaking WC Fields's rule about working with children and animals have obviously paid off for him.
But things weren't always so cushy for Cant. For some time after Play School and Playaway were suddenly and inexplicably axed - a fact that still rankles with him - he struggled to escape from children's-presenter typecasting. Perhaps directors couldn't believe he could do anything other than say, "Let's look through the... round window." He feared that, in career terms, there was to be no life after Play School. "I couldn't do anything at all," Cant laments. "It was difficult to get people to realise I'd stopped doing Play School and Playaway. These things hang on in people's minds. It took a long time to remind people I'd started as an actor in things like Z Cars, Dr Who, The Saint and Dixon of Dock Green."
Bit by bit, he resurrected his career in the theatre (he took 13 roles in The History of Tom Jones at the Belgrade Theatre, Coventry), in panto (he's just done his 16th successive year), and in voiceovers (he voiced Dappledown Farm for TVam). Lately, he has directed two of the children's shows for the newly opened Legoland, and written and voiced Animal Families for Channel 4.
As he looks through the nostalgic window back on his life's work, he feels "eternally grateful to Play School. It taught me an awful lot." Last year he went to the National Museum of Film and Television in Bradford to see the Play School toys that are kept there. "At one time I thought that might be where I'd finish," Cant muses. "I suppose I might yet end up there stuffed in some glass cabinet."
n The nationwide tour of 'The Canterbury Tales' opens at the New Theatre, Hull (01482 226655) tonight