After Margaret Thatcher came to power in 1979, she implemented an independent commission's proposal for public sector pay to rise by a thumping 26 per cent. Taxes went up, not down, and the Thatcherites later regretted their mistake.
If David Cameron becomes Prime Minister next spring, things can only get bitter for 4 million public sector workers, whose pay would be frozen in 2011. The Tory leader is hoping that people who tell opinion pollsters they want public spending to be cut to rein in Britain's huge budget deficit will accept their share of the pain.
But Labour ministers suspect that people may not necessarily translate their general view into a personal sacrifice. Not out of my wallet, thanks, could become the new Nimbyism. Ministers hope that their families and friends will be angry too.
"Vote for me, I'll freeze your pay" is hardly an election-winning slogan. Shadow cabinet ministers admitted privately last night that the Tories are taking a big risk. But Mr Cameron is determined to win a mandate for spending cuts. After yesterday's initial hitlist from the shadow Chancellor, George Osborne, no one will be able to say they were not warned.
The move breaks with tradition. Since 1992, when John Smith's "Shadow Budget" for Labour promised to raise national insurance contributions, openness in election manifestos has been out of fashion. Although his plans would have raised child benefit and pensions rather than filled a black hole in the public finances, the Tories converted them into a "tax bombshell" targeted at Middle England. Labour lost the election.
The Tories will not produce a "Shadow Budget", on the ground that they will not know the true state of the nation's books until after polling day. But they want to be "honest" about the sort of medicine they know they would have to administer. The £158bn a year public sector pay bill cannot be immune, they judge.
Shadow ministers are preparing for unpopularity. Yesterday I asked one of them how long their honeymoon would last after the election. "Two days," he quipped. He was only half-joking.
Yes, they could blame their inheritance on Labour for a while. Some senior Tories think they would get the benefit of the doubt for two years. Mr Cameron thinks he must hit the ground running, unlike Tony Blair who, the Tory leader believes, continued to act as an opposition candidate after becoming Prime Minister. The Cameroons think the first six months would be decisive.
Yesterday's package ensures a real debate about real cuts. The phoney war about paper clips and efficiency savings is over. Yet by boldly jumping first, the Tories leave themselves open to a Labour counter-attack, and possible criticism by independent analysts. An inevitable election-style war of words between the two main parties duly broke out last night.
The other risk in yesterday's declaration is that it will undermine Mr Cameron's attempt to position himself as a modern, "one nation", progressive Tory. Many people on £20,000 a year will not regard themselves as well off and able to take the strain of a pay freeze. Some on higher incomes may feel that those below them are being penalised, underlining Labour's attack on the Tories as the party of the "privileged few" rather than the "mainstream majority". And that could be dangerous.