Admissions staff have been straining to cope with this year's surge in demand as fears grow that the most popular subjects may soon disappear from clearing.
By Tuesday this week, the Universities and Colleges Admissions Service reported there were 113,240 potential students eligible to enter clearing, while 55,118 applicants were awaiting a decision or had yet to reply to an offer, and 328,605 had already accepted a place.
Many Russell Group universities have closed their books, the most popular courses at new universities are filling up and 3,687 students have so far withdrawn from this year's admissions round.
Ucas said that there were about 37,000 courses with vacancies, but each course "may have one or many places available".
Admissions officers told The Times Higher that the number of inquiries on clearing hotlines had rocketed, while numbers of applications for places on many courses have risen by more than 100 per cent compared with last year.
As well as law, psychology, economics and English, identified by Ucas as the most popular subjects, institutions have been inundated with applications for places on art and design, performing arts, teacher training, architecture, subjects allied to medicine, and social work programmes.
Ros Boyne, academic registrar for the University of Central England, said UCE received 30 per cent more phone calls than last year on the first day of clearing, and attendance at its clearing open day was up by 98 per cent.
Courses in medicine, subjects allied to health, English, primary teacher training and art and design are already full.
A spokesman for Surrey University said clearing hotlines had been twice as busy as last year and students hoping to get onto law, business and pre-medicine courses were being turned away.
Teesside University said it had received more than 3,600 inquiries through clearing, and the most popular courses, including nursing, physiotherapy and radiography, were full.
Connie Cullen, director of admissions at York University, said applications for management courses were up 200 per cent, while social policy applications were up 39 per cent, environment studies by 30 per cent, and physics, music and history of art by 15 per cent. The more popular courses had resorted to turning students away who did not match conditional offer requirements, she said.
Paul Tebbutt, admissions officer at University College Northampton, said applications were up 14 per cent, and courses such as social work were "unable to accommodate the increase".
Sussex University said the only courses it had in clearing were some science and engineering foundation degree programmes. Meanwhile, Sunderland University turned away applications for places in pharmacy and Staffordshire University had filled its psychology course.
Philip Robinson, director of University College Chichester, which saw a 20 per cent increase in numbers of applications compared with its usual annual increase of about 3 per cent, said the surge was having a different impact depending on where institutions were in the higher education "food chain".
Because Russell Group universities were taking in significantly more students, he said, institutions further down the chain were receiving more applications from students holding an insurance offer.
He said: "The difficulty we have is that we could nudge our intake up, but the areas where we have the greatest demand, such as performing arts, are those where we do not have the capacity to expand much further."
Kevin John, head of registry services at University College Worcester, which has placed 5 per cent more students than last year, said some students who had not got in should consider waiting until next year.
"For us it's not about squeezing in students, it's about helping them choose the right course at the right institution," he said.
But Matthew Andrews, senior assistant registrar at Durham University and secretary of the admissions practitioners group, warned that such a move should be carefully planned.
"Students need to think carefully about the likelihood of being accepted on the course they want next year," he said.