At first glance it looks like any playgroup or nursery class. Activities are carefully structured, and the children move from quiet, reflective occupations such as craft work or jigsaws to more lively activities involving songs, games, mime and movement. But there's one crucial difference. Throughout the entire two-hour session, not a word of English is spoken - at least not by the adults.
"Tu portes une robe rouge aujourd'hui ou bleue?" asks one of the play leaders or animatrices.
Three year-old Claire turns from her jigsaw to glance down at her dress.
"Pink, " is her succinct reply.
This is Tricolore Tots, set up two years ago by trained linguist Teresa Scibor and now running three times a week in various centres in London. The fact that the children regularly resort to English causes her no concern.
"When we play games to exploit familiar expressions, they love speaking French and there's no holding them back," she explains. "But to expect them to use it all the time would be unrealistic. On the other hand, unlike older children, toddlers don't worry if they can't understand everything. And because they hear so much French, their comprehension skills develop quite rapidly. It's the first step - C'est le premier pas. "
This was evident at the two sessions I visited last summer. Instructions - "Ne mets pas le crayon dans la bouche!" "Va te laver les mains!" "Prends du papier!" - accompanied by body language and visual clues when necessary, were accepted unquestioningly.
The benefits of starting a foreign language at an early age are not disputed, yet provision in English primary schools remains patchy. Even in Scotland, the introduction of primary languages nationwide has not been an unmitigated success, partly because of the shortage of suitably qualified primary teachers. Although in-service training is provided, linguistic expertise takes years to acquire.
"It's false to assume that a smattering of French is all you need to teach beginners," maintains Ms Scibor, who employs only fluent speakers. "One of the advantages of starting early is that young children are brilliant mimics. A poor linguist with an English accent instils bad habits that may never be lost."
Recognising that linguistic skills alone are not enough, she trains new staff herself in the basics of classroom management before letting them loose on a group of Tots or in her Club Tricolore for older children. One of her latest recruits, a native French speaker, is a case in point.
"The first time I watched her, she made all the classic mistakes - turning her back on the group, letting the confident ones dominate, allowing the pace to drag. I covered four sides of A4 paper that day, jotting down constructive criticism. We discussed it afterwards, and next time it was down to three. And so on it went, until finally I wrote nothing at all. I can now confidently let her take charge knowing that she won't let me down."
Another of the difficulties that the Scots have encountered is establishing continuity in the transition from primary to secondary. The same problem affects Teresa's prodigies when they outgrow the Tots.
Some get lessons at primary school, others join Le Club Tricolore where, although contact time is reduced, they continue to build up their vocabulary and confidence. Claire, the three-year-old with the pink dress, is even attending the French Lyce, as her parents are keen for her to become bilingual.
But there are also those who drop out altogether. While some would argue that her efforts have been wasted, Teresa doesn't agree.
"It's a great shame when they don't go on to build on what they've learned," she concedes. "But the value of early exposure to a foreign language is never lost altogether. At the very least, our children retain a positive attitude towards language-learning, which gives them a head start when they take it up again at secondary school. Half-forgotten vocabulary resurfaces, and their ear is already tuned in. "
Daniel Udy, the star of one of the groups I watched in July, is among those that didn't return in September. He simply has too many interests, and now that he has started school, he hasn't time to pursue them all. He will, however, attend Club Tricolore holiday sessions, which last for five days and cover a variety of activities.
"He has natural flair, and I don't want him to forget everything," explains his mother. "My older children have already taken part in holiday sessions and loved every minute.
She is also lobbying Daniel's school in the hope of persuading it to invite the Club Tricolore into the classroom - something some other schools already do.
Meanwhile, having built up a committed team of animatrices, Teresa is preparing to develop her other great interest - publishing materials.
She has already had some success in this field. French Start, an imaginative pack of games and tapes available through Living and Learning, has proved very popular and its sequel for younger children, French Tots, recently won a Good Toy award from Parents magazine. She has also exploited the club mascot, Zozo the flamboyant, disaster-prone clown. Zozo's Party is a cassette of catchy songs, and It's Fun to Speak French with Zozo - a colourful storybook with accompanying tape - was named Junior Book of the Week by the Daily Mail when it appeared in 1993.
Now, however, instead of relying on publishing houses, she is to launch into self-publishing.
Her first venture will be to turn the resources she has accumulated over the years into photocopiable masters for use in schools and clubs. But that is only the beginning.
"I've got so many ideas," she enthuses. "I'd love to do something based on Bastille day. or a Zozo guide to Paris full of colourful pictures and puzzles - wouldn't that be fun?"
Self-publishin g can be risky, but with so many willing consumers easily accessible to her, at least market research should be easy. Children have no qualms about letting you know what goes down well and what doesn't.
Information from Teresa Scibor, Le Club Tricolore, 10 Ballingdon Rd, London SW11 6AJ. Tel: 0171 924 4649 Fax: 0171 978 5312