SCOTTISH universities have come under attack over the gap in pay between male and female academics.

A new survey has shown a shortfall of more than £6,000 in the salaries of female academics across the UK, with the pay gap largest at traditional universities.

A report into the disparity by the UCU lecturers' union said: "Our universities promote equality as a core value, yet scratch beneath the surface and you find a sector bedevilled by shameful levels of inequality.

"Why is it that nearly 50 years after the Equal Pay Act we still have huge gaps in the pay of men and women? While the gender pay gap in higher education has fluctuated over the years, looking at the rate of progress over the last 10 years, it will take until 2050 to close the gender pay gap."

The report, Holding Down Women's Pay, comes after it emerged last month that Scottish universities have made no progress in smashing the glass ceiling for female academics in the past year.

Statistics collected by the Herald show just 22 per cent of professors at Scottish universities are women, despite the fact they make up 45 per cent of the academic workforce.

Last summer, Angela Constance, the Education Secretary, wrote to universities urging them to do more to break the glass ceiling for female academics.

The variety of barriers facing females in academia include a culture of long working hours, inflexible terms and conditions and pressures on researchers to produce academic papers in a way that can be incompatible with family responsibilities.

Many universities use short fixed-term contracts which can deter women because of the lack of security and there have also been warnings over indirect sexism where male professors "subconsciously" mentor and promote those that are similar to themselves.

UCU Scotland Official Mary Senior called on universities north of the border to do more to tackle pay inequalities - with institutions including Glasgow, St Andrews and Aberdeen coming under fire.

She said: "These universities should not allow such shameful levels of pay inequality to persist. We'd like to see a firm commitment from sector leaders to close the gap and are offering to work with institutions to put an end to pay inequality."

However, Scottish institutions questioned the figures quoted by the UCU and said a great deal of progress had been made in recent years.

Professor Verity Brown, vice-principal for enterprise at St Andrews University, said: "Our published figures for 2015 show that gender pay gap among lecturers in St Andrews is £173 per year which is nowhere near the figure of over £8,000 quoted by the union.

"We are committed to continuing to address gender pay gaps across all grades of staff and, like many universities, have made strong and significant progress in recent years."

A spokesman for Glasgow University said: "We are fully committed to gender pay equality for all of our employees and we work closely with the trades unions on this."

Meanwhile, Labour leader Kezia Dugdale issued a pledge for parity and said her party would go into the next election campaign with gender equality in the candidates they present.

Elsewhere, Olympian Katherine Grainger and First Minister Nicola Sturgeon will join forces to support the online International Women's Day campaign.

And a 19th Century nurse, poet and songwriter from Skeabost on the Isle of Skye has topped a social media poll of Outstanding Women of Scotland through the ages.