UNIVERSITIES which use zero-hours contracts to employ staff have been urged to outlaw the controversial practice.

Union leaders have written to institutions north of the Border calling on them to improve terms of conditions of employees.

The move comes after MPs on Westminster's Scottish Affairs Select Committee found thousands of employees were suffering "abuse and exploitation" on zero-hours contracts.

Its report said: "We are alarmed by the extent to which zero-hours contracts are used by Scotland's higher education sector.

"In some cases universities are being kept going by a staff who earn less than the minimum wage. The system of employment appears to us one of unashamed exploitation."

Since then, both Edinburgh University and Glasgow University have worked with the UCU Scotland union, which represents lecturers and support staff, to improve contracts of employment for casualised workers.

However, the UCU has now written to remaining institutions including Strathclyde, Glasgow Caledonian, Glasgow School of Art, St Andrews, Stirling, Heriot-Watt, in Edinburgh, Aberdeen, and Abertay, in Dundee.

Mary Senior, UCU Scotland official, said: "The widespread use of zero-hours contracts in Scottish universities continues to be an embarrassment.

"There has been some progress with Edinburgh University working with trade unions to address this and at Glasgow University we have negotiated a new policy which puts strict limits on the use of such contracts.

"The fact that our largest universities can commit to this shows that better workforce planning without zero-hours contracts is possible. It is now time that the other universities followed suit and made a serious commitment to end exploitative zero-hours contracts."

Gordon Maloney, president of NUS Scotland, said universities receive "over £1.5 billion of public funding every year" and it was vital that employees were treated fairly.

He said: "Earlier this year figures were revealed showing university principals cashing in on expenses worth well over and above the annual pay of many of their fellow staff, and every one of them in Scotland being paid more than the First Minister.

"To then see them continuing to employ staff on zero-hour contracts, denying them guaranteed work, and the terms and conditions many of their colleagues will enjoy, is indefensible.

"All employers need to have a serious look at the types of contracts they're offering, and ensure that all employees are being treated fairly, and have fair peace of mind when it comes to hours, pay and benefits."

A spokeswoman for Universities Scotland said: "University management are currently working with unions in a joint project to understand the extent of flexible contracts in the sector as well as how and why they are in use.

"Scotland's universities have already taken a stand against the use of exclusivity causes in their flexible contracts ensuring their staff can also make use of their flexibility.

"Where flexible contracts are in place it's important to understand the nature of many of these roles which usually includes seasonal or one-off work offered to students at events and conferences or the guest lecturer that comes in from industry once a semester."

The STUC said yesterday it estimated some 100,000 Scots are on zero-hours contracts which provide no guarantee of work.

Last year, the Scottish Affairs Select Committee report found a "two-tier workforce" was emerging across the UK as a result of the controversial approach to casual labour.

Staff who speak out against the arrangements can find their hours withdrawn or suffer bullying and harassment and bullying, the report found.

Scottish universities came in for particular criticism with 79 per cent of staff on the deals, compared with 53 per cent across the UK. This includes about 4,500 teaching staff in Scotland's colleges and universities, almost half the total in Scottish higher institutions.

John Swinney, the finance secretary, said that the Scottish Government "does not approve of zero-hours contracts" and would consider a "requirement in procurement contracts that zero-hours contracts cannot be used".

The UCU letter states: I am writing to you once more to invite you to commit to ending the use of zero hours contracts at your institution.

"When I first wrote to you on this issue in October 2013, I asked you to make this commitment and to begin discussions with the union with a view to phasing out the use of zero-hours contracts and other highly casualised contracts which offer no guaranteed hours within a 12 month period.

"Since then, I am glad to report that the universities of Edinburgh and Glasgow have conducted constructive discussions with us and we have been able to make significant progress on improving contracts of employment for casualised teaching staff at these two institutions."