As the Conservatives’ policy of handing commissioning cash to GP consortia comes under closer scrutiny, the lack of detailed thinking about how it will work becomes increasingly apparent.

If David Cameron wins the election GPs will manage “hard” budgets, as opposed to indicative budgets for money which at present is still in the hands of the primary care trust.

But the party struggles to explain when and how the consortia would draw down the money, and what would happen to the interest.

The interest could easily equate to tens of thousands of pounds a year for a typical consortium. The Conservatives maintain the money would have to be reinvested in patient care, but this would be all but impossible to enforce and a huge effort to audit.

There are also no guarantees about the wisdom of a consortium’s stewardship of commissioning money. Could it be invested unwisely and lost? If GPs are not allowed to invest it anywhere, then why not just give them an indicative budget, as at present?

With up to £70bn of the NHS budget at stake, the Conservatives must explain how this policy is going to work; very few people are convinced it will.

Hard cash makes Tory policy a soft target