David Cameron represents the "last gasp" of an old system that does not work anymore, Ed Miliband has told the Labour Party conference in Liverpool.
The Labour leader claimed Britain was crying out for a new kind of society in which the right people - responsible "grafters" - are properly rewarded.
And he vowed to fight for "a new bargain in our economy so reward is linked with effort".
"An economy and a society too often rewarding not the right people with the right values, but the wrong people with the wrong values."
He said moral decline was due to the way successive governments - including New Labour - had chosen to run the country.
Some of what Margaret Thatcher did - such as council house sales, punitive tax rates and ending the union closed shop and strikes without ballots - had been "right".
And New Labour also achieved much, he argued, but "we did not do enough to change the values of our economy," said the Labour leader.
And the result was a society in which vested interests such as the energy companies and banks prospered and the wrong people - such as Royal Bank of Scotland boss Sir Fred Goodwin - got the most rewards, argued Mr Miliband.
He earned loud cheers from delegates for attacking what he called Britain's "fast buck" culture - saying the country had to learn the lesson that "growth is built on sand if it comes from our predators and not our producers".
Now if Labour walks the talk when it most probably has a hand in shaping government policies in 2015 (either as the government or because the Tories are reduced to a minority government with the LibDems wiped out due to their feckless pact with Cameron).