NHS spending on agency workers has reached more than £300 million for the first time ever, with one health board spending nearly £750,000 on locums to cover just three surgeon shortages.

Scottish Conservative leader Ruth Davidson challenged the First Minister on the "spiralling cost of locums".

Health boards were forced to spend more than £310m in 2016/17 on locum doctors and agency nurses, an increase from £250m the previous year.

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During an exchange at First Minister's Questions, Ms Davidson said: "Just over a year ago, I asked the First Minister at First Minister's Questions about the spiralling cost of locums, medical staff brought in at huge expense because there aren't enough NHS staff to fill shifts.

"Last year the First Minister was clear health boards should minimise their use of agency staff.

"We'll, we've looked again at the cost of locum staff using Freedom of Information and it has now risen again, breaking the £300 million barrier for the very first time."

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It came as it emerged that NHS Highland had spent £737,000 on locum cover after failing to fill three vacant surgeons' posts for 15 months at Belford Hospital in Fort William.

The Belford is the busiest of the six rural hospitals in Highland because of traumas on mountains and roads.

In February 2017, NHS Highland bosses undertook a review of the job description in an attempt to make the vacant posts more attractive for the potential recruitment and retention of consultants.

However, none of the vacant positions at the hospital has been advertised for 15 months.

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A spokesman for NHS Highland said: "NHS Highland has made strenuous and repeated efforts to recruit substantive consultant posts, particularly surgeons, at the Belford Hospital for a number of years. Since 2014, we have advertised for three substantive and five locum surgeons.

"However, these repeated efforts to recruit consultants and the fact that we were unable to fill the posts made it clear that a different approach was required."

Nicola Sturgeon, a former health secretary, said the SNP Government had delivered record funding and record staffing numbers for the NHS in Scotland.

She said: "The combined medical and nursing agency costs represent just around two per cent of the overall staffing budget.

"Ruth Davidson might be interested to know that that is a third less proportionately than it is south of the border, where the Conservatives are actually in government."