The political parties often accuse each other of treating the voters like “fools” or “mugs”. After the MPs’ expenses scandal, such language plays well. Yet politicians are open to the charge of treating the public like fools when it comes to the number one challenge facing Britain.

The options for cutting this year’s £163bn deficit in the public finances should be a key issue of the election campaign. But MPs have conspired to delay discussion of the inevitable pain until after May 6. If the election had not been dominated by the leaders’ television debates, the parties would have come under more pressure to spell out detailed cuts before today’s landmark report by the Institute for Fiscal Studies.

But even before the first TV battle, it was clear that our politicians were reluctant to mention the d-word – deficit—other than giving general pledges to tackle it. They were happy to talk about “efficiency savings” but were anxious to maintain the fiction that these would allow “front-line services” to be protected. To be fair, the Liberal Democrats outlined £15bn of cuts, although £5bn of that would be spent.

There wasn’t a secret deal but Labour and the Tories arrived at the same point: austerity isn’t working. George Osborne, the shadow Chancellor, tested the market by spelling out some cuts at the Tory conference last October - including a pay freeze for some public sector workers and restricting tax credits and child trust funds for better off families. Mr Osborne won plaudits for bravery in the City of London. But the Tories took a hit in the opinion polls and – surprise, surprise - Labour accused them of clobbering middle income families. The Tories are still committed to these cuts but have been reluctant to add to the list.

Given the likely Labour reaction, you can hardly blame them. Yet the Tories abandoned the moral high ground by claiming that they could reverse most of Labour’s planned rise in national insurance contributions next year by conjuring up another £12bn of “efficiency savings” – with no detail provided.

Cuts are only half the picture. It is obvious that taxes will have to rise too. Yet the Tories prefer to talk about tax cuts - to reward marriage, reduce corporation and inheritance tax and block the NICs rise. They have “no secret plan” to raise VAT but their party has form.

The problem is that voters want action to “tackle the deficit” but not if it affects them directly. Six million people work in the public sector; many fear for their jobs. So the politicians serve up the motherhood and apple pie of efficiency savings and delay the menu of unpalatable options until the ballot boxes are sealed. It is a pity they could not have conspired in a more honest debate instead.