He is an older man: urbane, experienced and in a position of responsibility. She is a younger woman: immature, besotted and in a position of subservience.

That classic recipe for an unequal power relationship may sound like a desciption of the ClintonLewinsky affair, but it is also a scenario familiar to many teachers. Indeed, Lewinsky was castigated in one tabloid for behaving “like a desperate schoolgirl writing Valentines to a form teacher”.

So what is the right response from teachers - both men and women - to pupils who make advances? A spate of recent cases indicate that it is not only presidents whose judgment can lapse in the face of an ardent youngster.

At the start of half-term, a 31-year-old Yorkshire teacher walked into a police station with a 15-year-old girl pupil after a four-day absence. The pair disappeared after her parents admitted they feared that their daughter’s relationship with her teacher had developed into “more than a schoolgirl crush”. The man was arrested in connection with alleged child abduction and has been released on police bail pending further inquiries. On Monday, a Yorkshire council confirmed that a teacher had been suspended “pending the outcome of a police inquiry”.

Headteacher Alan Rainbow was jailed last year for indecent assault after he went to bed with a 15-year-old pupil. “For 26 years, I coped with girls with crushes on me,” said Rainbow, in Cardiff Crown Court. “But this one went disastrously wrong.” The judge told him:“You fell into temptation and you fell a long way.” Rainbow is now out of prison and “rebuilding his life”.

With a child under the age of consent, the rights and wrongs are clearcut. But when the pupil is over the age of consent, professional judgment can conflict with personal morality. Shairon Rodgers, a former English teacher at a Catholic secondary school, went to an Industrial Tribunal to claim unfair dismissal and sexual discrimination after resigning her job over an affair with a pupil, begun when he was 17. She said she had been “hounded out of the school by Victorian values”. “I’ve done nothing wrong apart from fall in love,” said Rodgers, a NUSUWT member. She lost her case.

In further and higher education, although professional ethics outlaw staffstudent relationships, in practice they are common. Steve was 36 and teaching English as a second language in a community college when he met a student he was attracted to. “It was somebody in my class, a beginner in English. She was a couple of years older than me, from the Middle-East, and spoke no English. I spoke a bit of Arabic and there was a good rapport between us. I was resistant to seeing her outside college, because it’s not done. But she was persistent, suggesting meetings, and eventually I said yes.”

They began a romance outside the classroom, but kept it secret. “Some colleagues would have been all right about it, but I didn’t want it to get out to my line manager because she would have used it against me.

“It wasn’t furtive, but it was weird. It set up an imbalance within the relationship and I felt it compromised my professionalism. I was pretending to treat the whole group equally but it didn’t feel very honest.”

Unhappy with the situation, he found a job at another college, and his one-time student then moved in with him. But, says Steve, the way the affair began had lasting implications which contributed to its end three years later. “We never recovered from that power imbalance. I was the one who organised things and that was always an issue between us. You start off with a lot of baggage in a relationship with a student, and it can be exploitative.”

Dan Vadnjal, 34, has taught economics at Cambridge University and elsewhere. When students have fancied him, he says he’s diverted it into work. “I tend to use that energy positively. I would still encourage the student to come and see me, but I wouldn’t talk about things that are personal.”

Others are not so strict with themselves. Vadnjal says: “These advances are often encouraged. You can lay the ground very easily. Academics work in single offices, with doors that are closed, and they have a lot of time.”

Adrienne Aziz of the Association of University Teachers has a hefty caseload of staffstudent relationships that have crossed over into the personal. “Inevitably, a large number of such relationships fade away. The injured party is then prone to say ‘my marks weren’t fair’. Or other students will say ‘this student is woman of the moment. It should have been me that got an upper second’.”

The best plan, says Aziz, is to distance yourself from vulnerability to allegations. “We suggest people go to their line manager and say there is a bit of tension here - could this student be supervised by someone else.” The AUT has put out guidance for members in a booklet on dealing with harassment.

Diana, a retired university lecturer, met her husband in the Sixties, when he taught her. He was 33, she was 21. Their affair raised some eyebrows, but was conducted openly, she says. “People are now more covert. I think there is more disapproval, because relationships are now more subject to analysis. There is no longer an automatic acceptance of the male prerogative.”

She says the serial seducer is a familiar figure on campus. “Many men go in for serial relationships, and you can see it happening. People would look over the new intake in September and see what the market was.”

For teachers in secondary schools, fears of being accused of sexual abuse of a pupil have changed working practices. “When I started teaching, we were encouraged to talk to kids on a one-to-one basis,” says Cardiff comprehensive teacher John Skelton. “Pastoral care was all the rage, but you wouldn’t do that now.” As tutor for Year 7 pupils, he says that every year a few pupils arrive with warnings from their primary school teachers - don’t find yourself alone with this pupil.

Judi James, a business trainer, is the author of Sex at Work, published by the Industrial Society to advise on workplace relationships. She compares the teacherstudent relationship to the doctorpatient one, with boundaries not to be crossed. “It’s one of those rather precious relationships,” she says. “It’s not like colleagues at work, however grown-up the student might be.”

James readily owns up to a long-ago crush on an art teacher at her all-girls’ school. “He was the only male teacher in the school. It’s the proximity, and the fact that they’re standing up performing.”

She says crushes from pupils should be taken seriously. “The feelings are real. A crush is condensed emotion.” But she warns against a direct rejection of a child. “However much of a nuisance they make of themselves, in relationship situations they’re always sensitive.”

Some may be looking more for a substitute parent than a lover. “Teachers can be seen as a replacement for emotional stability that children don’t have in their own lives. You have to deal with it professionally, but sympathetically,” says Mary Howard, legal officer at NASUWT. “Pupils can be hurt, and could retaliate with malicious allegations. It can be a minefield.”

The Government is currently consulting on the issue of relationships between young people and those in “positions of trust” - such as teachers, youth workers and substitute carers. A Home Office-led inter-departmental working group will report later this year, and the Government is expected to issue professional guidelines.

DEFENCES AGAINST ADVANCES

* Be aware of the possibility of crushes from children of the same or opposite sex - no one is immune.

* Relationships can be jokey and fun, but maintain a professional distance. Pupils are not your friends, even if close in age.

* Giving out home phone numbers, and engaging in out-of-school activities withstudents except as a group and in the company of other adults, may make you vulnerable.

* If you think there may be an infatuation, avoid sarcasm or confrontation with the child concerned.

* Inform management sooner rather than later. Part of the crush may involve fantasising and telling stories to other pupils, quite common in children.

* Beware of favouritism - this is disruptive to the class and may inadvertently foster a crush.