Cor blimey, prof. What made you do it?

`Stark staring bonkers.' That was the verdict on Colin Sumner when he gave up being a Cambridge don and headed for the fresh pastures of London's East End. John Izbicki investigated, and yes, he did it on purpose, and no, this professor isn't one sandwich short of a picnic by the River Cam ...

What makes an eminent don leave cushy Cambridge for a less privileged existence in London's East End? What induces him to swap a student-staff tutorial ratio of 2:1 for a class ratio of 19:1?

Some colleagues called Colin Sumner, 48, "stark staring bonkers" when he decided to abandon his post as lecturer at the Institute of Criminology for a chair of law at the University of East London. A shocked colleague told him he was "the first person in 700 years to leave Cambridge - er - voluntarily". And when he inquired what staff turnover there was at the Institute, the reply was a categorical: "There isn't one."

So what has this former polytechnic got that Cambridge hasn't? Professor Sumner, dapper behind a desk stacked high with papers, essays and reports, agreed that the offer of a chair and the remuneration that accompanied it were not irrelevant to his decision. But these were by no means the only grounds for his divorce from the internationally renowned research centre that had employed him for 18 years.

"I wouldn't have been promoted at Cambridge if I had stayed there for another 18 years. I was treated globally as a professor, but was never paid as such. There is an overall lack of promotion at Cambridge. One can be stuck at the top of the lecturer's scale for years and years," he declared. He added: "It became increasingly irritating to see academics at the new universities being paid between pounds 5,000 and pounds 10,000 more a year than their counterparts at Cambridge."

Cambridge, it would appear, comes gift-wrapped in myths. According to Professor Sumner, undergraduates are either crammed into crowded lecture theatres, or in a one-to-one tutorial. Seminars where, say, seven to a dozen students may discuss a problem and spark vibes off each other are almost non-existent. Yet Oxbridge is being spoon-fed an additional pounds 35m a year - additional, that is, to the kind of funding enjoyed (or these days, tolerated) by other universities - to support the luxury of a tutor- student tete-a-tete system.

"Cambridge is given a great deal of money, but it is rarely passed on to individual departments. In many ways the University of East London is better-equipped than Cambridge. Not all colleges are wealthy; far from it. There is Trinity College, among the richest, at one end, and Hughes Hall at the other."

Professor Sumner does not believe he will be the last to quit Cambridge. In fact, he forecasts a gradual shift of academics from the older to the new universities. "Many others are leaving or considering leaving," he said. They are in tune with the ideology of the former polytechnics - wider access to those who might have missed out on educational opportunities the first time round, and to those from minority ethnic groups. Cambridge, on the other hand, still cannot attract enough students from state schools.

Sumner feels that Cambridge treats its academics more as individual "consultants" than as members of a research team. "The job was getting too easy, and perhaps I was in it too long. I just felt I could have done so much more. But I was undervalued and over-administered."

So how does UEL differ? "Oh, in so many ways. One feels immediately at home. Everyone goes round smiling. And whereas in my social science lectures at Cambridge 99 per cent of the students were white and straight out of school, here it is a multicultural society, with 60 to 70 per cent in the law school from minority ethnic groups - a high proportion of them mature students. Well over half are women, whereas only about one in four studying law at my Cambridge Institute was a woman."

He describes East London students as "more aware, more streetwise, with good all-round experience". Most postgraduate work is part time, with police officers, journalists and administrators attending courses. "In Cambridge it was just like teaching at school. The students were fresher, certainly, and I'm not saying they weren't bright. On the contrary. But the work at UEL is at least as good, possibly even better. There's a wider range of perspective, mainly because so many UEL students have already experienced the world of work."

Frank Gould, UEL's vice-chancellor, certainly agrees with Sumner's view that too much public money is being pumped into Oxbridge to support the collegiate system and one-to-one tutorials. He wants the money (pounds 35m a year) used differently. "It could fund scholarships and bursaries to encourage bright men and women from lower-income backgrounds to enter higher education."