Students have always taken menial jobs during their holidays, of course, but dwindling grants and rising debt have forced more and more of them to work in term time as well. Universities that used to forbid term-time employment now run agencies to help undergraduates to find jobs.
According to new research for the National Union of Students and the GMB union, 700,000 full-time students now do part-time work. Half of them put in more than 12 hours a week and one in 10 does more than 20. Three- quarters are paid less than pounds 4 per hour, less than half the average male earnings.
While students' jobs used to involve helping out with the Post Office Christmas rush or checking the marks on GCSE or A-level papers, now they take place in far less congenial surroundings. Most are in nightclubs, pubs or hotels, all settings in which low pay and poor job security are common.
And in such places, students have fewer rights than their fellow staff. More than three-quarters of working students are doing the same jobs as permanently employed staff but only half are paid the same rates. Eight out of 10 get no holiday pay or sick pay, and four out of 10 have no meal breaks or tea-breaks.
This phenomenon, apart from having a major impact on the studies of the students involved and on student life, both social and political, is also contributing to the increasing casualisation of work in this country. One in five student workers has the chance to join a union, but fewer than one in 20 takes it up.
Chris Pond, director of the Low Pay Unit, says the use of students as cheap labour affects everyone in these jobs.
"It is an increasing problem. You have students trying to make ends meet with diminishing sources of finance and a loans system that doesn't meet their needs. They are looking for whatever work is available and they can be exploited.
"Students are being used to undermine the position of people who are normally in these jobs, and it has a downward effect on wages."
The Low Pay Unit's advice service has seen an increasing number of students in the past three years, though Mr Pond feels their numbers are surprisingly few given the scale of the problem. Perhaps most of them are simply hanging on, gritting their teeth and reminding themselves that it is only temporary, he says.
Most of these exploited employees, unlike those who work alongside them, can see a light at the end of their individual tunnel. But for each student who leaves university and finds a fulfilling, full-time job, there is more than one more undergraduate washer-up, doorman or pub glass collector desperate to fill the vacancy left behind.
When the night work takes over from the seminars
When he goes to work in the evening Howard Ford (right), a 19- year-old second-year history student at Manchester University, does not know whether he will be paid or not.
Howard works in a nightclub from 10pm until 2.30am every Tuesday night, but his wages depend on how much profit the organisers make. On a good night he takes home pounds 15, on an average night pounds 10 - pounds 2.20 per hour - and on a bad night, nothing at all. He has applied for countless better-paid jobs, he says, without any luck.
His duties are not onerous - he works in the cloakroom, taking coats - but the hours are anti-social and they have had a serious effect on his academic work.
"I have a seminar on Wednesday morning but I have missed a few because I am so tired. The tutors accept so much explanation but after a few times they don't want to know.
"I have had a final warning. I'm doing honours but they have threatened to relegate me to an ordinary degree."
Howard is not alone. Many of his friends are working, like him, to pay the bills.
"One of my friends is an overseas student who works for an accommodation agency. This week she's worked about 30 hours for pounds 50. She's in severe danger of failing her exams."
You could call it a smashing job ... with terrible wages
Douglas Trainer, president-elect of the National Union of Students, knows all about low pay and dirty jobs. As a barman in an inner-city bar in Glasgow, one of his jobs was smashing the empty beer bottles for recycling.
No gloves or protective clothing were provided, and staff did the job by breaking one bottle against another, often sending shards of broken glass flying.
"I got to do a lot of the scummy jobs because I was a student," he says. "I spent about an hour a week doing that."
Douglas worked for 20 hours in the bar each week, between lectures for his English and politics degree course at Strathclyde University. He also worked in a supermarket for pounds 1.45 an hour and in a food co-operative for pounds 2.30 an hour. Many of his fellow students were doing the same.
"Employers are becoming aware of the dire straits that students are in and they are aware of how far they can push them. They know how little they can offer to pay, and what poor conditions they can put them through."
The NUS is encouraging student workers to join a union so that they can seek proper job protection.
"Ideally, we want to see students' jobs as just being for extra spending money," says Mr Trainer.
Howard Ford, who works in a club: 'My tutors have threatened to relegate me to an ordinary degree' Howard BarlowReuse content