For teachers, it is the hottest of topics. Everyone has a view on it, each of them different. Forget funding, pay, vocational versus academic. This is the real educational deal: what should a lecturer wear in class?

Some colleges have tried to lay down the law. Strode college in Somerset, for example, has a professional code for employees and, tucked away at the end, are five lines on “professional appearance” which look like open-house for the legal profession: classroom staff are told to be “smartly dressed at all times” and warned that “very casual clothing” will not be tolerated.

North East Surrey college of technology was in the news last year when part of its recovery plan after a poor inspection report involved a dress code banning jeans and “female flesh”. With re-inspection due shortly, getting the college to comment was a bit like asking the Iranian government about its plans for nuclear weapons. “It’s a sensitive issue,”

said a spokeswoman, “not something we want to keep returning to.”

Someone who does want to talk about it though, is image consultant Fiona Ingham. Her profession these days has a place in our collective hearts alongside tax inspectors, traffic wardens and estate agents.

All that changes, Fiona says, once people in general - and teachers in particular - hear what she really has to say.

“Teachers really enjoy my sessions,” she says. “They tend to be sceptical at first - they say things like “what’s this all about?” - but, by the end, they are telling me how much more they like it than the usual courses they go on.”

Fiona runs short courses on self-presentation for a whole range of educational establishments - schools and higher education colleges like Westminster university and the Cranfield school of management - as well as working in FE. She always starts by pointing to a piece of research about initial impressions. Some 55 per cent of these, she says, are based on a person’s appearance, 38 per cent on their voice and only 7 per cent on what they actually say.

“Teachers are astounded, if not horrified, when they are told that,” she says. “But what you look like affects entirely how your students perceive you.

“Teachers might say that clothes shouldn’t matter, but I point out to them that you never put on anything accidentally. Other people look at you and know you chose it, know you bought it.”

Fiona talks a lot about confidence and authority. If the teacher looks and feels confident and authoritative, then students will perceive this too.

“This is especially the case with young teachers,” she says. “If they look as if they are in charge, then they’re already in a good position.”

So what can we put on to give ourselves an authority boost?

“Always wear a jacket,” is Fiona’s first rule. “A person in a jacket looks in charge.”

Not surprisingly, she confirms that the outfit for men which carries the most sartorial clout is the dark suit, combined with a pale shirt. For a woman, once they have donned that ubiquitous jacket, it’s “something at the neck, a belt, a watch, shoes in good condition”.

What you carry into class with you matters too. The bag-lady look favoured by some is a definite no-no.

“It shouldn’t be a carrier bag or anything that is grotty or in a bad state. And if you carry a rucksack you’ll look like a student and they’ll treat you accordingly.”

Fiona acknowledges that dress, like everything else, moves on.

Smart-casual, she thinks, is fine in the classroom, as long as it is smart and not what she calls “decrepit casual”.

Here we find the usual suspects - jeans, baggy T-shirts, any garment with a “distracting” logo on it.

“You can still look good, still dress to your personality and be dynamic in casual clothes,” she says. “The continentals don’t have any problems with it. They know how to accessorise and properly put on the smart-casual look.”

Finally, we come to the crunch. How would she characterise what teachers really do dress like? There is a long pause.

“The heads and their deputies have learned that it matters,” she says diplomatically. I decide not to tell her that’s she’s talking to someone who hates jackets and whose only image consultations to date have involved Mrs Jones shaking her head and saying: “You’re not going to college dressed in that, are you?”

Fiona is uncertain too about the wisdom of colleges actually imposing dress codes on teachers.

“It would have to be carefully thought through,” she says. “Perhaps they could try for a basic minimum, but people get hot under the collar about it. It’s a bit of a taboo.”

Fiona’s caution on this was echoed by a head of department in a large FE college I consulted.

“It would be awful. I really don’t agree with it,” she said. “At the management level it’s a good idea, as it’s obviously a symbol of authority, and managers need that little bit of distance between the staff and students they deal with. But in the classroom the only real question is, ‘Is it impacting on teaching and learning?’ If it isn’t then leave well alone, because if lecturers are happy and comfortable then they’re more likely to do a good job.”

Students I talked to on the issue seemed similarly relaxed. One or two complained about teachers in the 40-plus bracket being stuck in an era of “sandals and socks, nylon, polyester and viscose skirts and blouses”, but most seemed happy with what those who taught them wore.

“Above all it’s the person inside the outfits that counts,” said one.

Aah! Now isn’t that just what we like to hear?