A fifth of universities are regularly facing recruitment difficulties, a new survey has revealed.

The survey, by the Universities UK group of vice chancellors, also found that 60 per cent faced problems employing lecturers "some of the time" - with a third facing the same problem with professors.

Low pay was cited as the main cause of the shortages, which were found to be most prevalent in the areas of law, engineering and information technology, where academics could earn more in the private sector.

Education and health academics were lured away from the higher education sector by higher salaries in the other areas of the public sector of schools and the NHS.

Retention of lecturers and professors was a daily problem for eight per cent of universities, up from 2.2 per cent in 1998.

Older universities were found to face more acute problems than former polytechnics, while many institutions across the sector had problems recruiting and retaining clerical and administrative staff and technicians.

"What is of concern to all universities is ensuring that our students, whatever their background, have a high quality experience," said Baroness Warwick, the chief executive of Universities UK.

"That requires university teaching to be informed by research, provided by high quality and motivated staff, in buildings fit for purpose and using modern equipment."

The group called for an extra £10 billion investment in higher education to tackle the difficulty.

In response, a spokeswoman at the department for education and skills said that extra investment was already planned.

"We are investing an extra £1.7 billion in higher education over the six years to 2003-04 - an increase of 18 per cent in real terms, which shows our commitment to higher education," she said.

"Funding per student has risen in real terms this year for the first time in a decade."

"But we do recognise that institutions work hard to recruit and retain academic staff. We have made a start to help universities by providing £330m over three years to support increases in higher education pay.

"This will help improve the quality of teaching and learning and modernise management and reward systems. We will continue to work with the sector to build on this progress."

However, Liberal Democrat higher education spokesman David Rendal warned that the government would be, "condemning students to a bargain-basement higher education", if extra funds were not made available.

"40,000 new university teachers will be needed if the Government is serious about meeting its 50% participation target. And that is simply to maintain the existing student-staff ratio of 18 to 1, let alone reduce it," he said.

"Instead the Government has presided over real term cuts in funding and a crisis in the recruitment and retention of university staff. This is a record to be ashamed of."

The general secretary of the National Association of Teachers in Further and Higher Education, Paul Mackney, said: "The report's findings make it absolutely clear that in both old and new universities there are major recruitment and retention problems for mainstream learning staff."

NUS national president, Owain James, called for funds generated through student loans and tuition fees to be directed towards improving academics' pay.

"This government is yet to realise that if it wants to realise its aim of widening participation it needs to support the education sector. More students entering higher education means greater demands placed on already over-worked staff," he said.

"Given that students have seen the cost of going to university double over the last four years, they are angry that none of that money has been used to pay staff properly.

"It is not surprising that more and more academics are opting to work in the private sector, and it is highly unlikely that the new generation of graduates will decide to stay in the sector when they are saddled with debts, on average, of £12,000."

General secretary of the Association of University Teachers, Sally Hunt, claimed that the survey was a warning of crisis in the higher education sector.

"Today's graduates are fully aware that they can earn more money in the private sector than working in poorly paid research or teaching jobs," she said.

"Academia is an ageing profession with many crucial departments, such as engineering and chemistry, already over-populated with staff approaching retirement age

"It is time for ministers and vice-chancellors to end the rhetoric and provide universities and students with the money that the sector desperately needs."