A-level students who miss their expected grades this summer will face a frantic scramble for places, with many top universities already warning they are full.

Clearing, the process which matches students that have been turned down by their original choices due to lower grades to other courses, is expected to be short this year, with limited opportunities available.

Very few places will be available at the UK’s top Russell Group institutions.

Cambridge, Oxford, London School of Economics (LSE) and University College London do not use clearing, neither does Edinburgh University.

In addition, Birmingham University said it would not have any places available through clearing, and both Bristol University and Imperial College London said they were not expecting to enter the process.

Glasgow University said there would be no clearing places available, apart from a small number, expected to be less than 100, for liberal arts and teaching courses at its Dumfries Campus.

And Cardiff University expects to have fewer than 200 clearing places available.

A spokesman for Manchester University said the institution would have fewer than 50 places available, a similar number to last year.

Sheffield University said it had “not yet finalised it’s clearing strategy”. but a spokeswoman added if the institution does enter clearing it will be for a “limited” number of places.

And a Warwick University spokeswoman said: “We can’t make final decisions on clearing places until after results. At this stage it’s looking very unlikely that we will have any places; if we do, we will not be lowering our standard grades but will expect people to attain the same grades as those who are admitted through the standard processes.”

It comes just a day after Universities Minister David Willetts admitted that top A-level students face being turned away from this year amid mounting competition for degree courses.

He said the Government had made an extra 10,000 places available this year.

But he added: “It is going to be tough. There are young people who sadly are not going to get a place, including perhaps some young people who really have got good A-level grades, and for them there is a whole range of options.”

Mr Willetts suggested sixth-formers consider retaking exams or applying for apprenticeships instead.

More than 660,000 people had applied to start full-time undergraduate courses by the end of June - up nearly 12 per cent on last year’s record-breaking figure.

It has been estimated that as many as 170,000 would-be students will be left disappointed this summer.

Last year around 47,600 students accepted places through clearing, according to figures from the university admissions service, Ucas.

A spokeswoman for the vice-chancellors’ umbrella group Universities UK said: “The increased pressure on places this year does mean that competition is likely to be more intense and it will be a challenging time for everyone.

“It is anticipated that the clearing process for this summer will be briefer and tighter than in previous years.

“However, universities are very experienced in handling high numbers of applications and they have been preparing for this peak time for many months now along with Ucas.

“Applicants may need to be more adaptable in their clearing and adjustment choices again this year. This emphasises the need for everyone involved - whether that is universities, schools or colleges - to provide as much advice and guidance as possible to applicants. It will be important that students do not rush their choices.”