THE NHS is facing a "retirement timebomb" as figures show almost a fifth of Scotland's nurses and midwives are set to retire in the coming decade.

Staffing figures show that 12,000 nurses and midwives are now aged 55 or over, equivalent to just under 18 per cent of the national total.

A mismatch between the number of young recruits entering the profession and those approaching retirement age means the workforce has been steadily ageing.

Within midwifery alone, the share of staff aged 50 or older rose sharply from 32 per cent in 2011 to 42 per cent by 2015.

In some areas, such as the Highlands, the proportion of nurses aged 55 and over is already more than 21 per cent.

Donald Cameron, shadow health secretary for the Scottish Conservatives, who compiled the statistics, said: “We can't afford to be caught cold by this.

“Older nurses are invaluable for their commitment and experience, but these figures show we can’t rely on them forever.

“The SNP didn't plan properly for an ageing population, so it must learn those lessons and make plans for an ageing workforce.”

It comes after figures revealed a surge in the number of agency nurses plugging gaps on Scotland's hospital wards, from 200,000 hours of cover in 2012/13 to more than 500,000 hours in 2015/16.

Last year, Scotland's health boards spent £158m paying for temporary nurses to cover shifts, up £12.5 million on the previous year.

Theresa Fyffe, director of the Royal College of Nursing (RCN) Scotland, said: "There is already a vacancy rate of 3.6 per cent which shows that health boards aren’t able to find the nursing staff they need. So a lot of nurses retiring around the same time is going to add extra pressure to a system that is already creaking at the seams."

Ms Fyffe said older nurses chould be encouraged to stay longer by redeploying them away from the "physically demanding" frontline care, while continuing to increase the number of student nurses to "help break the ‘boom and bust’ cycle that has blighted the nursing workforce".

It comes after a report by the Royal College of Midwives last year warned that while there was currently no shortage of midwives in Scotland, the outlook was worrying.

It stated: "More, younger midwives are needed if we are to avoid a serious problem in the near future caused by the retirement of so many midwives.

"It might feel difficult to justify when there is no current shortage of midwives in Scotland, but if nothing is done to address the age profile issue there could be serious consequences for the quality and even the safety of Scottish maternity services."

Student nurse intakes for 2016/17 increased by 5.6 per cent, the fourth year-on-year rise.

The Scottish Government has also committed to create 1000 additional training places for nurses and midwives.

Health Secretary Shona Robison said: “Under this Government, NHS staff numbers have risen significantly, with record number of consultants, nurses and midwives and allied health professionals now delivering care for the people of Scotland.

“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.”