Glasgow is facing a nursing "retirement timebomb," opposition politicians have warned.

Figures show more than 18 per cent of nurses employed by NHS Greater Glasgow and Clyde are aged 55 or over, a rise of 5 per cent since 2011.

It means that nearly a fifth of the workforce could be retiring over the next decade.

The latest figures show out of 17,108 nurses working in hospitals in the Greater Glasgow area, 3122 (18.25 per cent) are over 55.

The Scottish Conservatives, who released the figures, accused the SNP government of failing to prepare for an ageing NHS workforce at a time when boards are facing a recruitment crisis.

Aileen Campbell, Minister for Public Health said NHS staffing levels have risen to "record levels" and said national and local workforce planning was designed to take future retirement figures into consideration.

Health workers union Unison accused the Tories of failing to acknowledge the impact of Westminster reforms and pension cuts which they said were forcing NHS staff to work beyond the age of retirement.

The party's Glasgow MSP Adam Tomkins said: “There’s no question that the NHS in Glasgow benefits from the experience and commitment older nurses bring.

“But we can’t rely on that forever, and these figures clearly show the NHS in Glasgow is facing a retirement boom.

“Over the next decade, the health board is going to lose about a fifth of its workforce to retirement, and that’s going to be an incredibly difficult gap to fill.

“The SNP hasn’t prepared properly for an ageing population, so the least it could do is start planning for an ageing nursing workforce.”

Unison's regional organiser, Matt McGlaughlin, said: "The Tories clearly don't understand the impact of their own reforms.

"Many people are now being forced to work much longer because they are too poor to retire.

"It is their government that provides the funding for the health service in Scotland.

"If there is a shortage of staff or a lack of preparation you can lay the blame squarely at the door of austerity.

"Our evidence is that staff who have retired are coming back to work a couple of days a week. They are still fit and able and have a lot to offer.

"The UK government have actually been engaged in a large piece of research.

"If you are going to have to ask to people to work longer because of pension changes, how do we make that a positive experience and ensure they are better supported and trained."

Aileen Campbell, Minister for Public Health and Sport, said: “Between March 2015 and March 2016, Nursing and Midwifery staffing in NHS Greater Glasgow and Clyde has risen by 108.5 whole time equivalent posts.

“Under this Government, NHS staff numbers have risen to a record high level, with more consultants, nurses, and allied health professionals now delivering care for the people of Scotland. 

“National and local workforce planning is designed to take into account future retirements. 

"In December 2015 we confirmed a 5.6% increase in trainee nurses and midwives for 2016/17 – a fourth successive rise. We have also made a commitment to create 1,000 additional training places for nurses and midwives. 

“This government has also committed £450,000 over three years to reintroduce a national return to practice scheme. The scheme is well underway and has already attracted around 160 former nurses and midwives who wish to get back into the profession.”