Tony Blair and Gordon Brown are the "Arthur Daleys" of British politics, according to the Conservative leader.
Blair and Brown are trying to con voters, says Duncan Smith
Iain Duncan Smith used a speech on Tuesday to launch one of his fiercest attacks on the men at the top of the government and say the Tories were on the way up.
The prime minister and his chancellor are like the "dodgiest" car dealers in the television series Minder, trying to "con" voters about their policies, the Tory leader said.
Mr Duncan Smith underlined the accusation made in his party's new advertisement campaign - that Labour wanted to raise taxes.
Millbank Tower - Labour's former headquarters - is the venue for the speech ahead of the start of Parliament's summer recess later this week.
Party aides said they wanted to show they would take the fight into "Labour's citadel", where the New Labour project began.
Mr Duncan Smith said: "Why cannot this government deliver the
better life they promise?
"The reason is that Tony Blair and Gordon Brown are the Arthur Daleys of
British politics - the dodgiest of used car salesmen, trying to flog a
clapped-out, broken-down model for change by slapping on a new coat of paint.
"They tried to con middle Britain into believing that their policies were
conservative, and that you could have a conservative government without a
"They dumped some unpopular Old Labour policies. But although the language
changed, their instincts did not. They remain: to over-tax, over-regulate and
Mr Duncan Smith claimed the prime minister lacked the conviction to bring about real reforms.
"He sings the song of change as if change
were an end in itself," he said.
"He says delivery is on its way, but he said the same thing in 1999, 2000,
2001 and again last year.
"There is a sense of drift and decay about this government which no number of
relaunches will reverse.
"It has run out of steam. The prime minister is running out of friends.
And the British people have had enough.
"People have seen New Labour spin give way to New Labour lies. Is it any
wonder no-one believes a word they say any more?"
Mr Duncan Smith also delivered an upbeat message about his own party's fortunes.
About the Tories, he said: "I see a party with a
renewed sense of unity and purpose.
"When the election comes, we will be ready, different from today's Labour government based on spin and squander. We
must meet the trial of competence and conviction.
"We are witnessing the beginning of the end for New Labour - diminished by
spin, damaged by broken promises, the Third Way does not deserve a third
"As our chance comes we must be ready, united and determined. We will deliver
a fair deal for the people of Britain."
After the speech, Labour Party chairman Ian McCartney said that the
Tories under Mr Duncan Smith were now "more extreme than ever".
"Over the past year he has broken with the Tories' election pledge to match
Labour's spending on schools and hospitals," Mr McCartney said.
"He has pledged to take over £2bn out of the NHS to subsidise private
healthcare for a privileged few.
"And he has committed the Tories to 'across the
board' cuts of 20% in the vital public services which help to educate Britain's
children, care for the sick and elderly and win the fight against crime."