When teacher Andrew Jones was convicted of drink-driving he expected the regulatory body for the profession would take an interest.

“I had one other conviction for drink-driving five years ago,” he said. “That was why they looked into it and I can understand that.”

But Mr Jones (not his real name) was still surprised by the punishment he received from the General Teaching Council for England.

He had already been fined Pounds 300 and disqualified from driving for three years by magistrates.

He expected the GTC to give him a reprimand, which would remain on the register for two years and he would have to declare to any employers. But the disciplinary tribunal panel decided this was insufficient. On top of the reprimand, it ruled he must go on a drink drivers’ awareness course. If he failed to attend before reapplying for his drivers’ licence, he would be forced to attend another tribunal, which might suspend him or strike him off the GTC register.

Mr Jones said he found it odd that the GTC should impose an extra punishment which the magistrates’ court had not deemed necessary. “I would have understood if they said I was not allowed to drive a minibus or drive as a teacher,” he said. “Everybody I spoke to afterwards was of the opinion they gave me a harsh punishment.”

The tribunal panel members, who meet in Birmingham, said they were unsure whether the teacher had “sufficient insight” into his actions, although they did acknowledge that he had apologised and regretted the incident.

“Coming out with argument that I was `not sorry enough’ made me feel they were judging moralistically, and that was not their place,” Mr Jones said. “It was their place to look at the safety of students and if I am a professional person.”

Mr Jones is one of dozens of teachers who have been referred to the GTC for offences that occurred outside of work, more than a third of which involved driving. His punishment was, in fact, lighter than that given to several other teachers caught drink-driving.

The professional body has avoided using a tariff system, so has treated each case on its own merits. For example, Stephen Crawford, an art teacher from Kent, was allowed to continue teaching provided he submitted medical evidence to the GTC proving his abstinence. But Sarah Brown, who taught in Wolverhampton, was banned for two years - although she was also convicted of driving a stolen car.

For teachers, the main category of transgression is motoring offences - largely drink-driving - closely followed by dishonesty, ranging from theft, shoplifting and burglary to benefit fraud and some false declarations on forms. Violence, including threats, assaults and manslaughter, is the third largest category. Drugs and firearms offences and one example of inappropriate behaviour make up the remaining cases.

One teacher can be responsible for several offences, which is why the number of incidences that the GTC examines is bigger than the number of cases it hears.

Last year 506 cases were referred to the GTC and 150 were heard. These involved 222 incidents of misconduct, 55 of which occurred outside of school. The total number of outside of work incidents has risen sharply since the hearings began in 2002, with only six heard in 2003. But the increase has been in line with the rise in total cases.

This suggests more widespread awareness of the GTC regulations among schools and local authorities, rather than greater misbehaviour among teachers.

Chris Keates, general secretary of the NASUWT, said: “It is more in the consciousness of employers that the law requires any criminal convictions of teachers to be referred to the GTC. In the past people did not necessarily understand that.”

The types of cases the GTC takes to a formal hearing are guided by its code of conduct. The code states that isolated road traffic offences would “not normally be considered as behaviour incompatible with being a registered teacher”.

The council considers whether there is a pattern of reoffending it believes requires further action. It lists benefit fraud, indecent assault, inflicting grievous bodily harm, manslaughter, possession of prohibited firearms and ammunition, threatening or disorderly behaviour and unlawful wounding as offences that are relevant to determining a teacher’s fitness to practise and looks at cautions and convictions.

Most of the out-of-school incidents that the GTC punished fell within the parameters of the code, given that they were either in the list of offences or, in the case of most of the drink-drivers, the offenders had been convicted more than once.

But if out-of-work offences have already been punished by the courts, when is it appropriate for the GTC to hand out additional punishment?

Should teachers be banned from the classroom for a year for theft when the police only saw fit to impose a caution? Or suspended for three months for filling in rent details on a fraudulent housing benefit application for someone else?

Mick Brookes, general secretary of the National Association of Head Teachers, points to the case of one of his members. Paul Davies, head of Cwmdare Primary near Aberdare in south Wales, was jailed for dangerous driving after a collision which left another driver in a wheelchair. He had to wear an electronic tag when he first returned to the school.

The GTC for Wales initially banned him for teaching for three years, but this ban was lifted on appeal. Mr Brookes said: “If he had been in any other job he would have taken his punishment and served his time. Why would he have to lose his job as well?

“Clearly anyone found guilty of offences against children is unfit for teaching, but where do you draw the line with other offences?”

John Dunford, general secretary of the Association of School and College Leaders, said the reputation of schools can be hurt by teachers’ behaviour outside the classroom, so it is right to bring some of these cases. However, he urged a “proportionate response, which could be nil for very minor offences”.

Ms Keates said the regulator’s judgment had improved over time in the cases it chose to hear, but there were areas of procedure that could be tightened up. She is concerned about disciplinary panels in schools and local authorities, which hear many misconduct cases before referring them to the Department for Children, Schools and Families. She said many teachers feared they may not get a fair hearing before school governors because they may be reluctant to oppose the headteacher if the governing body was bringing the case.

She hopes that there will be greater clarification of the types of criminal convictions that are relevant to the teaching profession and which incidents should be referred from local panels to the DCSF.

Education law experts have also expressed concern about the quality of evidence that is gathered during local hearings and forms part of the information sent to the GTC.

Jenni Watson, a law consultant who has represented teachers before the GTC on several occasions, said the quality of investigation at a local level is “abysmal” in most cases. She thinks the GTC does not spend enough time checking whether evidence stands up to scrutiny before deciding on a formal hearing. “It puts teachers in a position where they are presumed guilty and have to prove their innocence,” she said.

“I see too many allegations which turn out to have little substance and ruin people’s lives.”

Anita Chopra, a partner at Match Solicitors, said teachers are not paid costs if they are cleared by the GTC, as they would be in a court case.

The GTC agreed that it had received a growing number of referrals but does not believe the change in the number of cases constitutes a trend as it has 500,000 teachers on the register. David James, head of professional regulation at the GTC, said there had been “no significant change” in the number of hearings on misconduct outside the workplace.

“All cases, both at the investigating and hearing stages, are judged on their individual circumstances and according to a framework agreed by the council,” he said. “We conduct all GTC hearings in a fair, unbiased and considered manner, and always in the public interest.

“Independent advice is provided to each committee in the form of an independent legal adviser, and committees are guided in their decisions by the GTC’s code of conduct and practice and indicative sanctions guidance to ensure consistency.”

The GTC is about to rewrite its code of conduct and it will cover behaviour both inside and outside the classroom. A consultation to discuss what it should contain was due to be launched today. The consultation period will provides teachers with the opportunity to tell the GTC how far it should be able to reach beyond the school gates and how it should handle the cases it takes on.

The question is so tied to individual moral values that views are bound to differ. But some, like Mr Jones, will argue that the punishment should be better fitted to the crime.