RISING energy prices and a need to maintain facilities such as hospitals and schools must underpin spending by public bodies, watchdogs have warned.

A new report also warns that reducing staff costs, so far the main method by which public agencies have been reducing spend, was not sustainable.

Instead, the Auditor General for Scotland and the Accounts Commission claims councils, the NHS and other public agencies had to focus more on priorities and improve long-term planning as finances "remain tight".

While the public sector had so far "coped well" with spending cuts, the report claims local government and health boards will continue to "face significant challenges". They warned: "Irrespective of the outcome of the 2014 referendum on Scottish independence, pressures on finances will remain.Those leading and managing public services will face increasingly difficult choices about how to spend the money that is available."

The amount of cash the Scottish Government has control over in its budget has fallen by 9 per cent in real terms, from a peak of £31.9 billion in 2009/10 to £28.9bn in 2014/15, and is "expected to reduce further", the report said.

It adds: "Increasing demand from an ageing and expanding population will continue to put considerable pressures on public bodies."

Rises in energy prices, and a need to maintain facilities such as hospitals and schools also had to be considered.

Auditor General for Scotland Caroline Gardner said: "With further pressures expected and the demand for services increasing, public bodies need to look again at how they set budgets and focus on their priorities."