Tory adviser Sir Peter Gershon suggested these ‘immediate savings' can be made by tightening controls on public sector recruitment, as well as through a freeze on major new IT spending and renegotiation of contracts with suppliers of goods and services.
He also suggested the savings could be made without affecting the quality of frontline services.
‘There should be a very robust approach to controlling recruitment across the public sector - using natural turnover to cut costs and redeploying existing staff to the vacancies that are agreed to be essential,' he said.
But Howard Catton, head of policy at the RCN, said the idea nursing teams can stretch and make do in this way is a ‘flawed assumption'.
‘The idea assumes slack in the system, that if you don't fill a post other colleagues can easily cover and this won't have impact on patient care. That's a big assumption to make, and I'm sceptical that there is that degree of slack in the system,' he said.
RCN's primary care advisor Lynn Young said: ‘If David Cameron is going to be ruthless about not appointing front line staff, then he will be diminishing front line services. It's pernicious that people would not be replaced, and it's as alarming as making people redundant.
‘We will be on our guard and scrutinising about what decisions are being made on reducing expenditure.