Colleges and schools in England will struggle to introduce government reforms designed to ensure that more students leave with qualifications in mathematics and English, their leaders have warned.
The policy has been badly planned and underfunded, they claimed, as it emerged that a former senior adviser to education secretary Michael Gove fears that it could lead to students studying for "lots of crappy" qualifications.
From this term, any student in post-16 full-time education without at least a C in English or mathematics at GCSE must continue to study the subjects until they make the grade.
But Brian Lightman, general secretary of the Association of School and College Leaders (ASCL), said: "This is being done in the context of cutbacks, no new money and no national plan for an enormous initiative. Literacy and numeracy are really important, but where is the plan to make sure that all young people get access to this?"
Joy Mercer, director of education policy at the Association of Colleges (AoC), said that further education colleges will need 2,100 extra staff to teach the courses. The funding system has been changed so that colleges will be financially penalised if students without the requisite grades do not continue to study English and mathematics.
But Ms Mercer said colleges are not being given the extra funding needed to recruit teachers with the necessary experience. "Colleges are desperately worried about how many staff they have got and about how they are going to get (the new courses) into the timetable," she said.
The government has said that students should "ideally" be studying for GCSEs in the subjects, but they may also take other qualifications as a "stepping stone" towards that goal.
This week Sam Freedman, a former special adviser to Mr Gove, responded to a claim on Twitter that, in practice, the English courses studied "could be basic". "Yep," answered Mr Freedman, now director of research at charity Teach First. "My fear is lots of crappy level 2 equivalents just to secure the funding."
The change comes as the new compulsory participation age becomes law - young people are now legally obliged to continue in education or training until the end of the academic year in which they turn 17. It will be raised again to 18 in 2015.
In theory, the change should bring the country up to the standard of many other advanced nations in terms of education participation (see panel, left). But in practice, it could amount to part-time, work-based training. Experts are warning that without fines for those breaking the rules - as was proposed by the last Labour government - the legislation could be ignored.
A survey carried out in May by the ASCL and the Department for Education found that fewer than one in 10 school and college leaders felt there had been adequate information about raising the participation age. Nearly a third said they were unaware that all post-16 schools and colleges were "under a duty to inform the local authority if a young person drops out of learning".
The AoC has found that nearly two-thirds of colleges will now need to offer extra mathematics and English classes to more than two-fifths of their students.
Skills minister Matthew Hancock said that "in most cases" the necessary teachers are "in place" to run the extra courses.
"At the moment there are more than 250,000 people who leave school each year without a C in English or maths, and 90 per cent of them don't get that by the time they leave education at the age of 19," he added. "It is a big and important change."