It would be “irresponsible” to promise the NHS’s budget can be ringfenced, Welsh first minister Carwyn Jones has said.

He said spending on Welsh hospitals would be protected, but he could not guarantee funding for the rest of the health service would be shielded from cuts.

Speaking at question time in the Senedd, Mr Jones said the Welsh Assembly’s budget is being squeezed by the Barnett formula, which is used to set the level of funding Wales receives from the Treasury.

The future of the budget will not be known until the comprehensive spending review on 20 October, he said.

Mr Jones was tackled by Tory leader Nick Bourne who said there is a “cloud of secrecy” over health spending. Mr Bourne said the Assembly government had been unwilling to deal with claims that up to a fifth of its health budget - about £1bn - was misspent.

The first minister said: “We have said that we will look to protect hospitals.

“We can’t give a commitment about the entire health budget because the Barnett squeeze through convergence is hitting us very, very hard.

“It would be irresponsible of me to suggest that we can ringfence the entire health budget, especially as we don’t know what financial settlement we will receive from the UK government on 20 October.”

He rejected Mr Bourne’s call for an independent spending review.

“My view is that it’s the job of the National Assembly to scrutinise the Welsh Assembly government and you don’t need another independent quango to do it as well,” the first minister said.

He was also forced to again defend health minister Edwina Hart about a leaked document from management consultants McKinsey into the NHS.

Mr Jones last week cleared Mrs Hart of misleading the Assembly by allegedly withholding McKinsey’s findings.

“She is the most open minister this government has,” he said.

“She goes out of her way to inform members via emails or correspondence of what’s going on in the health service and it does surprise me that there’s any suggestion of any suppression of anything that’s going on in the health service.”