Universities have been accused of evading their moral responsibilities by employing contract staff on the minimum wage.
Jane Wills, professor of human geography at Queen Mary, University of London, worked with a coalition of faith and community organisations to persuade universities to pay their cleaners a "living wage" of £7.45 an hour rather than the minimum wage, £5.73.
After representations that the minimum wage, which equates to £11,173 a year for a 40-hour week, was not enough to live on, Queen Mary agreed last year to raise the hourly rate to £8.68 and to bring its cleaning and security services back in-house. Several others have since followed its lead.
Professor Wills' analysis showed that the cost of cleaning increased from £2,119,000 in 2006-07, when the service was still contracted out, to £2,197,000 in 2008-09. But her research also found that the service had greatly improved.
She said: "There is an arguable business case for (paying a higher wage) but the college has gone further than it needed to because of the moral case. People are evading their moral responsibility by blaming the market and arguing that the business case wouldn't allow it."
Ray O'Halloran, head of the estates department at Queen Mary, added: "We were not innocent; we knew that people were doing two or three jobs to survive. We wanted to set a higher standard."
Other London institutions have taken similar approaches, including the School of Oriental and African Studies, the London School of Economics and Birkbeck, University of London, which agreed in March to pay its cleaning and catering staff £7.45 per hour.
Keith Harrison, Birkbeck College secretary, said: "Staff and students will face some price increases ... as a consequence but seem prepared to accept this given the reason."
Despite the campaign's successes and its focus on the "moral obligations" of institutions, church-foundation universities are split on the ethics of the matter.
Robin Baker, vice-chancellor of the University of Chichester, whose cleaners are all contract staff on the minimum wage, said; "Our first responsibility - including morally - is to provide best value for money for our students and the taxpayers who fund us, while fulfilling our legal and social responsibilities.
"This means, among other things, at a time when the unit of resource is being squeezed, moving as much investment as possible into frontline services where the students obtain the benefit."
The University of Gloucestershire employs a mix of in-house and outsourced cleaners. "Our own are comparatively well paid ... however we have no control over what the outsourced cleaners that we use are paid," said Patricia Broadfoot, the vice-chancellor.
She added: "Universities generally are struggling at present to control their costs in order to protect jobs, which in itself is a moral issue."
Canterbury Christ Church University employs most of its housekeeping and security staff directly and pays them more than the minimum wage. Michael Wright, its vice-chancellor, said: "Universities have a responsibility to provide a positive working environment for staff and to support their local economy."