Scotland’s Auditor General Caroline Gardner warned in a new report that recruiting the skilled staff required for the Scottish government’s new financial and social security powers and responsibilities will be “challenging.”

The report said around 50% of spending will be raised directly in Scotland by 2020 following the Scotland Acts of 2012 and 2016.

A number of new responsibilities – including around £3 billion of annual social security payments – are also being devolved.

Gardner’s latest Scotland Acts report acknowledged the “huge” task the changes present, and said the Scottish government’s social security programme had made good early progress.

But the Auditor General said much more remained to be done.

Her report warned that it will be challenging to recruit people with the right financial planning, IT and economic skills in time to meet the complex demands of the new powers.

In particular, setting up a social security agency and delivering the first wave of devolved benefits by summer 2019 will be difficult, she said.

The Auditor General also found that the Scottish Government has not clearly estimated the total cost of putting the new powers into practice or how much it will exceed the £200 million contributed by the UK government.

The extra cost will have to be funded from the Scottish budget.

The report also said the new powers “bring far greater budgetary risks as well as opportunities as a result of the greater emphasis put on the performance of the Scottish economy.”

A UK withdrawal from the European Union would add extra uncertainty.

To manage the risks, the Auditor General’s recommendations include calling on the Scottish Government to agree the governance and organisational arrangements of the new Scottish Exchequer.

“Putting the Scottish Parliament’s new financial powers and social security responsibilities into action is a huge and highly complex piece of work,” said Gardner.

“More detailed workforce analysis and a much more transparent picture around overall costs are needed to ensure the right people and infrastructure are in place in time.

“Good early progress has been made on the government’s social security plans but they are now at a critical point.”