The Conservatives have turned to the domestic agenda with a bid to win over middle class voters.

Party leader Iain Duncan Smith used his keynote speech at the Conservative spring conference to promise a "fair deal" to middle Britain.

He claimed the voters that had defected to Labour in 1997 had given the government a fair chance but were now angered by tax rises and a failure to improve public services.

Duncan Smith signalled the party was likely to fight the general election on a tax-cutting agenda.

"Conservatives appreciate you have to be fair to the people who pay for the public services and for society's other responsibilities," he said.

He also set out his vision of a "one nation" party that would have at its centre an "agenda for fairness".

"Our party - the party of Burke, Disraeli and Shaftesbury - fulfils its greatest purpose when it upholds fairness for every person in Britain," he said.

"Not only for the disadvantaged, but for the hard-working, law-abiding, patriotic majority who deserve a fair deal too."

Duncan Smith said it was possible to have a low tax enterprise economy and better public services as well as an inclusive society.

His core message was to the middle classes who, according to the opinion polls, have yet to be convinced that the party has modernised.

He praised the people who were "the quiet strength of our nation" - volunteers, small business owners and other law-abiding citizens.

"They are forgotten by this government, except of course when Gordon Brown wants their money,'' he said.

"But they are the quiet strength of our nation and, yes, they are getting angry. These people are the backbone of our country and the government has ripped them off."

The public had now experienced "wake-up moments" such as council tax rises, National Insurance rises and the A Level fiasco.

"For six long years the British people gave Tony Blair the benefit of the doubt. But there is no doubt now. Tony Blair's day of reckoning is fast approaching. The British people are ready for change."