Heads in Britain may boast that they run “extended schools”, but they have not taken the idea as far as South Korea. Its pressured education system still tops international league tables, but a high price has been paid in suicides, lost youth and endless cramming.

So far, students and parents have borne most of the pain. But now it’s the teachers’ turn. In response to parents’ demands, state schools in Seoul are starting to offer 14 hours of teaching - lessons from morning to night, taught by staff who are already some of the planet’s most diligent and overworked professionals.

While teachers in countries with saner education systems are waving pupils goodbye, the unlucky teachers at some South Korean schools must prepare to do a bit more - a further five unpaid hours, to be precise.

The idea is to end pupils’ reliance on evening classes at private colleges, which have all but replaced the formal education provided by state schools. Children have come to see day school as a safe but dull place where they can catch up on sleep.

They and their parents believe the real action occurs in the nightly cramming classes, where they prepare for the sacred university entrance exams.

The person who devised the scheme is Kim Yeong-suk, a principal who persuaded 30 colleagues to volunteer for the new 7am to 10pm-plus day - without being paid overtime.

Government officials have hailed her as the Joan of Arc of the whiteboard, dedicated to pushing back the perfidious cramming system that has made a mockery of public education.

Children at Ms Yeong-suk’s school were told to drop cramming classes - which at least gave them a change of air once a day - and prepare themselves for studies until 9pm every day, even Saturdays.

So far, the academic results have been good. That means more parents will be lining up to relocate their children’s fact-stuffing from the comparatively friendly, well-equipped crammers to this country’s unprepossessing state schools.

Ms Yeong-suk starts work at 7am and leaves at 11pm. She has been promoted and is now being pushed as an exemplar for all public school teachers. If teacher unions had hit squads, she would now be their prime target.

But so far, staff have been curiously muted about the extension of their service and the fact that their free time is being sacrificed. They are wise.

To ask why would invoke fury from politicans and parents, who attack anyone who dares to criticise their right to lobotomise pupils through cramming, or even to give their children up for adoption to boost their schooling.

The quality of education has also been given scant reflection until recently. This is not surprising as in South Korea it doesn’t seem to matter what you know, but what certificates you’ve amassed from prestigious colleges or - in some famous cases - had faked.

The public demands only that all pupils have equal access to qualifications. And if that means 14-hour days for teachers, too bad.