By Sean Coughlan BBC News Online education staff

When you hear of illegal child labour, the leafy suburbs of Surrey might not be the first place that springs to mind.

But in recent months, the county has seen some of the highest-profile prosecutions for child labour offences so far seen in the United Kingdom.

There is a clear link between children working too long hours and problems in their education

Ian Hart, child labour law enforcer

A McDonalds' restaurant, Woolworths, Tesco, Safeway, Burger King, Odeon Cinemas, Heritage Hotels, Fourbuoys and Thorpe Park amusement park have all been successfully prosecuted.

What is believed to be the biggest ever fine for such offences was imposed on a McDonalds' franchise holder in Camberley.

The �12,400 penalty followed an investigation that found school pupils working up to 16-hours a day, in what was described as a "fast-food sweatshop".

Child labour law enforcer

The man behind this crackdown is Ian Hart, child employment officer for Surrey County Council's education welfare service � one of only a dozen such full-time enforcers of child labour laws in the country.

After 30 years in the police force, he is now tracking down, raiding and catching employers who ignore the strict laws governing child labour.

"There is a clear link between children working too long hours and problems in their education, such as poor attendance and low attainment," he says.

And he points to the example of McDonalds, where - on school days - 15 and 16 year olds were beginning shifts straight after class and then worked through sometimes until 0200 hours the following morning.

On Saturdays, a 15-year-old girl was starting work before 0800 and working through until 0120 the next day.

"When were these children meant to do their homework? When did they rest? This was the year when they should be studying for GCSEs."

At the prosecution of Tesco earlier this month, Mr Hart had called on the court to recognise the educational damage caused by young people working up to 2230 after school, warning that they would be inattentive and tired at school the next day.

Work permits

All 16 year olds and younger need to have permits before they can work � and he is worried about the safety of pupils working illegally.

"If these children don't have work permits there is no way of monitoring their safety where they are working, or indeed whether their parents are even aware they are working.

"It is most disturbing that they are unlikely to be covered by the employer's insurance."

There are about 2,500 permits issued in Surrey, and they allow 13 to 16 year olds to work for two hours on school days, with restrictions on the type of work allowed, including bans on work in commercial kitchens or using dangerous machinery.

On Saturdays, 13 to 14 year olds can work for five hours and 15 to 16 year olds can work up to eight hours.

Tip-offs

Tip-offs about children working illegally come from schools, parents, members of the public and Ian Hart has a sheaf of allegations, naming pupils who are out working when they should be in class.

I followed him for a day, as he followed up reports of under-age employment, arriving unannounced and taking the firms involved by surprise.

BBC News Online's Sean Coughlan was not welcome at the Wentworth golf club

And the first call was the exclusive Wentworth golf club, near Ascot.

Arriving at the plush club house reception, we waited beneath the watchful gaze of a painting of Sir Winston Churchill and a photo of the Duke of Edinburgh, before a frosty encounter with managers.

When Mr Hart explained that he was following up claims made against the club � and I was observing him for the day � it was made very clear that my presence wasn't welcome and I was told to leave.

The club evidently didn't want to discuss this with a journalist present � and in effect, I was thrown out.

But talking to Mr Hart afterwards, he said that the club told him that there were no breaches of child employment regulations. And he accepted their assurances.

Hairdressers

The next visit took us to a hairdressers in Ashford, where it had been reported that a schoolgirl was working illegally.

A receptionist refused to confirm that the girl was working there � and refused even to give her own name. And she claimed to have no knowledge of any managers or any contact details for the owners.

But with years of experience as a London policeman, Mr Hart was undeterred by such stonewalling, and says that if necessary he will go back and observe such workplaces, sitting outside in his car at 0700, waiting to see who goes into work.

"I'm not going to be pushed around. I owe it to the children," he says.

Chip shops

Following reports from a local school, the next visit was to a chip shop in Sunbury. And confronted with the allegation, the manager admitted that there were two school-age youngsters working without permits.

The hours being worked were only slightly over the legal limit, and in this case it was agreed that the shop would ensure that the youngsters would apply for permits.

As a cross-section of cases, he says this was not unusual � one getting a clean bill of health, another still to be determined and one business caught with two illegal employees.

As well as his prime responsibility of protecting children from exploitation, he also says such visits help to raise awareness and is a warning to businesses that the council is enforcing the child labour laws.

With local unemployment running at only 2%, businesses are struggling to find staff � particularly at the lower end of the pay scale.

And he is determined that children's education should not become the victim of such pressures.