Another university could join 13 Scottish institutions taking strike action, a union has warned.

University and College Union (UCU) Scotland members at the University of the West of Scotland (UWS) are being asked to back industrial action in a ballot that closes on January 28.

The disputes centre on changes to the Universities Superannuation Scheme (USS) and issues over pay and conditions, with some institutions involved in both disputes and others in only one.

If UWS staff vote to take part in the action over pay and working conditions they will join UCU members at 13 other Scottish universities who finish the first eight days of strikes on Wednesday.

The union has warned if the disputes cannot be resolved then more strikes are likely in the new year, with more members eligible to take part and more universities and students affected.

Dr Christopher O'Donnell, UCU secretary at UWS, said: "We'll be asking members at UWS to say yes to strike action and be ready to join strikes in the new year should they be necessary.

"Nobody wants to take strike action and the incredible support seen for the action at universities so far should force universities back to the negotiating table with serious offers to resolve the disputes without further disruption."

The union said members at 12 institutions across the UK are being reballoted for strike action.

UWS is not part of the USS and voted against strike action by a narrow margin in the previous ballot over pay and conditions.

The universities affected are Heriot-Watt University; the University of Aberdeen; the University of Dundee; the University of Stirling; the University of Edinburgh; the University of Glasgow; the University of St Andrews; the University of Strathclyde; Glasgow Caledonian University; Glasgow School of Art, Queen Margaret University; the Scottish Association for Marine Science, and The Open University in Scotland.

They are among 60 institutions across the UK taking part in the walkouts.

Carol Costello, speaking on behalf of USS employers, said previously: "Under pensions law, the scheme needs more money to keep benefits at the same level - which has always been a key demand of the UCU.

"Many institutions will not be able to afford a higher share of the contributions, and the costs and risks of this scheme are shared equally by all.

"We will continue to talk with the UCU, as we have done over the last 18 months, on a joint and fair solution to this pensions dispute."

A UWS spokeswoman said: "We fully support the ongoing UCEA (Universities and Colleges Employers Association) and UCU discussions in relation to what might be done to resolve the three non-pay elements of this dispute."