Can sisters still do it by themselves?

New Hall's library is falling down. Which would be bad news for any Oxbridge college. But for a modern women's college, without the legacies and endowments of an older college, it is a financial disaster.

The college was founded in 1954 to expand opportunities for women at Cambridge. In 1965, it moved into an architecturally adventurous complex, with a dome and a sunken courtyard, on the northern edge of the town. But these concrete buildings have proved to have a catastrophically short lifespan. The college was already facing a repair bill of £6m when the librarian noticed ominous cracks spreading across the library vault. To repair it will take a further £1.3m, which the college hasn't got, and which it is unlikely to be able to raise from its small and not particularly affluent alumni community.

"Our finances are pretty ropy," admits the admissions tutor, Owen Saxton. "It is a huge worry at the minute."

There are only three remaining women's colleges at Oxford and Cambridge – St Hilda's at Oxford, and Newnham and New Hall at Cambridge (Lucy Cavendish College is also single-sex, but for mature students only) – and all face difficulties. They are unpopular with applicants, who mainly want to go to mixed colleges; they don't all offer the full range of subjects; they hover at the bottom of college tables of academic results, they are geographically out of the way, and they suffer from damaging popular perceptions that they are either the equivalent of girls' boarding schools, or that they are lesbian or Muslim enclaves.

And all are strapped for cash, with some carrying much heavier staffing costs than the mixed colleges, because an obligation to employ female Fellows means they can't share appointments with other colleges.

In short, it would seem practical for these last bastions of women's higher education to throw in the towel and go mixed. At least one seems to be heading that way; New Hall already has both men and women Fellows, and in-house support for its single-sex status has plummeted. A poll of its students carried out in the last academic year found only a narrow margin still in favour, and observers say privately that it is unlikely still to be women-only in 10 years' time (although, in the near term, it is busy looking to supporters of women's causes for funds).

But Newnham, whose finances and applications are healthier, and whose roots are deep in the 19th-century struggle for women's education, would find it harder to take such a decision. "We would never just look at student opinion," says the principal, Onora O'Neill. "We would have to look at all the long-term implications for students and for a whole variety of constituents. It's not currently top of anyone's agenda."

And St Hilda's bears the burden of being the only women's college left in Oxford. "The issue of the preservation of choice is very important," says Judith English, the principal. "There is a small proportion of students, many from traditional Asian or Muslim backgrounds, or from overseas, who would simply not be able to come here if it wasn't for us." But she expects that recruitment and financial pressures will soon bring up the question of a mixed Fellowship again.

About half of students taking up places in the women's colleges actively don't want to be there – their applications were handed on from mixed colleges. But once there, they often come to see the advantages. They are forced to plunge into university life, and so end up with wider circles of friends than those who stick to their own college scene, and they also tend to gain senior positions at the universities' unions and clubs. "I know very few people outside my college, whereas I spot New Hall girls all over the place," says one Clare College undergraduate.

"And having a women-only base to go back to is very empowering," says Helena Puig Laurrauri, who came to study at Oxford from Spain. "I'm reading PPE (Philosophy, Politics and Economics) and a lot of women drop economics because it's so male-dominated, but I got lots of support and encouragement from my tutor to carry on with it." When St Hilda's held a poll on going co-ed three years ago, 78 per cent of the students and 86 per cent of the academic staff voted to keep the status quo.

But the issue of academic standards haunts students and Fellows. Critics mutter that having women-only colleges means that more marginal girls get places than marginal boys. New Hall remains dogged by a historically abysmal performance on University Challenge. And everyone is twitchy about results. "When they came out this year, people couldn't talk about anything else," says one Newnham insider. "Everyone's very sensitive about it."

Saxton says: "Our students can brush off being called nymphomaniacs or lesbians, but they get very upset at the charge that they are thick and second-rate."

In fact, undergraduates at women's colleges perform as well as women at all the other colleges (ie not as well as men). And New Hall, which has always prided itself on taking risks with applicants from unconventional backgrounds, points out that league tables that measure all three or four years' of exam results give a false picture, and that the college does much better than others at adding value to final results. "Some of our students are less well-prepared when they come to us, but by the end, they are doing very well indeed," says Saxton. Research also shows that first-class degrees may be more linked to money than gender, with the richer colleges doing best, while many also point out that league-table differences are only tiny anyway.

All the women's colleges feel a duty to stand fast against the continuing male dominance of Oxbridge, especially after watching in horror how quickly some former women's colleges changed when they took in men. Numbers of men and women undergraduates might now be edging towards parity, but, when it comes to Fellows, the pyramid tapers sharply. In 2000, only 19 per cent of Cambridge lecturers, and 6 per cent of professors, were women. More worryingly, the atmosphere in some labs and departments can still cause women undergrads to switch from subjects such as physics as soon as they can. In this climate, women's colleges feel a continuing missionary zeal to support women students and preserve opportunities for female Fellows, as well as to widen access, and pay attention to issues such as childcare and college nurseries – about which most of the former men's colleges still don't want to know.

But the issue of going mixed is unlikely to go away. Even though most Oxbridge academics are publicly supportive, in private they question why there should still be women's colleges when there are no longer any men's ones. And students say that some undergraduates find them claustrophobic, and the activities of their assertive gay minorities intrusive.

Wendy Stone, who was at Newnham in the Sixties, and whose daughter is now there, can see both sides of the question. "Remaining true to the memory of the women who fought for equality in women's education is not something we should give up lightly, and I feel this is particularly important for the current generation of students, who are less aware than we were of the opportunities they have given us all." On the other hand, she sees that changing times demand different solutions and that many now feel that the struggle for equality should be carried on in the mainstream. "So I do wonder if we might have to embrace co-education as a way of securing a continuation of those principles.

"It also gave me the confidence to believe that anything's possible if you're prepared to fight for it, which may have been partly due to the feeling that you had to defend St Hilda's throughout your time there – from people saying things like: 'Do they teach law at St Hilda's? I thought you only did cooking and childcare,' which was actually overheard during a law lecture."

'St Hilda's provided me with enduring friendships, and there are alumni networks'

Jenni Marks, 28, a lawyer with the City firm, Allen & Overy, read jurisprudence at St Hilda's from 1993-1996.

"I chose St Hilda's because I went to an open day and liked the people I met. I'd always been to co-ed schools so I had no sense I needed to rush out and meet men. We had a vote in the Junior Common Room which resolved that the college should stay single-sex. There were always people in two camps, but what was noticeable was that although people often arrived not having wanted to be at a women's college, by the third year most people were really happy with the college's status. I remember people saying it was amazing how quickly the atmosphere of Somerville changed when it went mixed, with beery lads throwing up in the corridors.

"Hilda's girls always seemed to know more people in other colleges. If women's colleges don't do as well academically it's probably because women know there's more to life than study. We were always out and about, being proactive, getting involved.

"Looking round, you often wouldn't have known it was a women's college. I think the only rule was that you couldn't have a guest stay more than three consecutive nights. Though being a women's college probably made it harder to have those sort of close male friendships where you sit up all night over coffee agonising about the world.

"St Hilda's gave me enduring friendships. I'm still in touch with 20 or 30 people regularly, and there are alumni networks in areas like law and business. And it opened a career door because the wife of the guy who interviewed me for my present job was at Hilda's so that broke the ice, although the legal world is quite 'old boys' Establishment', so the Oxbridge card probably helped as well."

education@independent.co.uk