She began her teaching career determined to make a difference to the youngsters in her charge. Her stunning looks and sexy short skirts certainly turn heads among the teenage boys, who drop books deliberately to peer up her skirt or glance down her cleavage.

There is one troublemaker in particular who she believes can achieve, despite his bad-boy behaviour. So she offers him extra coaching after school to help with his GCSEs, paid for by his mother. Within weeks he has turned a new leaf and starts working hard.

But the 16-year-old picks up the wrong signals from the attention she pays him. He develops a crush on her, and cannot accept his feelings are not reciprocated.

At the end of one tutoring session, he pulls her to him and kisses her passionately. At first she responds, but then pulls away as she realises her mistake.

This is not a true story but a plot from Hollyoaks, the popular teenage drama serial. However, it is typical of the trap that young teachers can easily fall into, especially when around teenage pupils who are not much younger than themselves.

Last year, the National Union of Teachers acted for 30 of its members under investigation by the Department of Education and Skills for allegations of inappropriate relationships with a pupil. Many more cases were dropped when it was found that teachers had fallen prey to malicious claims by students who had lied or misinterpreted their actions.

The Education Secretary has the power to bar anyone from the classroom found guilty of “behaviour which involves a breach of a teacher’s position of trust, such as a sexual or otherwise inappropriate relationship with a pupil, regardless of whether the pupil is over the age of consent”.

Last month, a teacher was jailed for 15 months by Stafford Crown Court for having sex with a 14-year-old boy who developed a crush on her. Her career is in ruins, and the 31-year-old married mother of two will now be registered as a child sex offender for 10 years.

Becca Hayton, the naive teacher in Hollyoaks, could also face dismissal and criminal charges for her relationship with the pupil, Justin Burton.

Kate Myers, author of Teachers Behaving Badly? which examines issues of teachers and sexual behaviour, said Becca had made errors which could land her in deep trouble.

Ms Myers, emeritus professor of education at Keele University, said: “The teaching profession needs people like her who believe they can make a difference. There is nothing wrong with offering extra tuition. Young teachers may need the extra money and the pupils can benefit. But she should discuss the situation with her mentor or head of department and let them know exactly what she is doing.

“By allowing the boy to kiss her she has done something really silly, but as long as she deals with it properly now, she should be all right.

“She must tell someone in authority at school and get advice from her union, so that if complaints are made, she has a note of the story from her perspective on record.

“She should explain the situation to the boy as calmly and kindly as possible. She should also inform his mother she cannot continue with the tutoring and decide whether to explain why or not.”

Becca should also have dressed more appropriately. Ms Myers said: “Pupils will warm to her, but she should be mindful that she will be dealing with hormonal adolescents coming to terms with their sexuality often by fantasising and sometimes practising their social and sexual scripts.

“She needs to think carefully about how she presents herself and how it will be perceived by the students. There is a line between being frumpy and old-fashioned and being ‘one of them’, which as their teacher she is not.”

Graham Clayton, the National Union of Teachers’ senior solicitor, who also contributed to the book, said teachers behaving like Becca laid themselves open to criminal proceedings under breach of trust offences introduced five years ago. “Employers are likely to take a dim view of this kind of behaviour,” he added. “Any relationship between a teacher and pupil which leads to close physical contact is likely to result in detailed consideration of the facts with a tendency to impose some kind of disciplinary penalty.”

He said a teacher finding themselves in that situation could face criminal proceedings, though this was unlikely if the physical contact so far had been nothing more than just kissing.

Alternatively, he or she could be dismissed and their case referred to the General Teaching Council or the Department of Education and Skills which will then consider if they are a fit person to hold a registration.

DO dress professionally, not provocatively. Save flip flops, bare midriffs and hooded tops for weekends.

DON’T offer extra tuition out of school without discussing it first with a senior colleague.

DO tell a senior member of staff immediately if a pupil has gone too far with you by touching you inappropriately, or letting it be known that they fancy you.

DON’T send sexy electronic messages to pupils, as even jokey texts can be misinterpreted. Inappropriate texting and emailing between teachers and pupils has been cited as a concern by the General Teaching Council’s disciplinary panel.

DO get advice from your union immediately you suspect a pupil may complain about you, either because they have misinterpreted your actions or are being malicious. It is important to get your version of events recorded as early as possible.

DON’T give pupils your phone number, your address or other personal details. It is likely that these will be passed around and lead to problems for you.

DO be kind to a pupil who develops a crush on you, but explain calmly that your relationship can never be anything other than professional.

DON’T be tempted to go on a date with a pupil, whatever their age. You could be committing a criminal offence and may lose your job and professional reputation.