Paul John, director of the Institute for Fiscal Studies, said the effects of further spending cuts on government departments already having their budgets slashed would be "hard to contemplate" and it was more likely that "protected" departments would be hit in the next parliament.
The effects of concentrating all those cuts on currently unprotected areas of public service spending look hard to contemplate.
A more likely scenario perhaps is that other choices will be made after the next election.
Taxes could rise, hitherto protected elements of public spending, like the NHS and pensions, could be hit, or the date at which we reach fiscal balance will be pushed further out.
More top news
Tougher regulations coming into effect today are intended to crack down on motorists driving under the influence of drugs.
A Finnish punk band whose members have autism and Down's Syndrome have been chosen as the country's entry for the Eurovision Song Contest.
The PM promises to double to 200,000 the number of homes built under an existing scheme aimed at easing Britain's housing shortage.