David Cameron today insisted that allowing the Government to fail was not good enough for a Conservative Party that must convince the electorate to vote for "bold" change.

In a surprise appearance on stage at the Tory conference in Manchester, the party leader told delegates “to go out and win” the next election.

“We will not let Britain down,” he said, insisting that the Tories were now the party of the environment, the NHS and employment. "This is not some week of celebration, but the week we should look the British people in the eye."

He told members that they must not talk to themselves but needed to address the country, something he claimed Labour had failed to do at their conference last week. Mr Cameron said of Labour's attacks on him: "If the charge is youth and energy, I plead guilty."

He said the Government was tired and “clapped out” and must be swept away.

Mr Cameron claimed the Conservatives were offering what he said was “the biggest, boldest programme to get Britain working that this country has ever seen”.

His rallying cry came as the party outlined a number of policy initiatives. George Osborne, the Shadow Chancellor, announced that a Conservative government would abolish tax on jobs created by new businesses in their first two years in power.

The temporary tax break would mean any new business would pay no Employer National Insurance on the first ten employees it hires during its first year.

Mr Osborne claimed the initiative would create 60,000 additional jobs. “Getting Britain working will be a top priority for the next Conservative Government. We have to end Labour’s jobs crisis, which has left one in five young people unable to find work,” he said.

Last night Mr Cameron announced that more than half a million people on incapacity benefit would have their payments cut by more than £25 a week under plans to force them to find jobs. As he tries to wrest back the initiative over welfare reform — and head off an internal party row over Europe and the Irish ratification of the Lisbon treaty — he promised that a Conservative government would go farther and faster than Labour in tackling joblessness and benefits dependency.

It will be the first time that a party has gone into an election promising such drastic cuts for so many people.

This morning, Jim Knight, the employment minister, said that the proposed savings were already included in Labour plans. He said the Conservatives were interested in cutting the benefit bill, not the people affected.

"We do believe savings can be made in the longer term and these are factored into Treasury plans. But this is not a quick fix," Mr Knight said.

"The only way the Tories can make £600m savings quickly is by rapidly cutting payments for people who cannot possibly work.

"Having lumped people off unemployment on to sickness benefit in the previous recessions, now the Tories want to rush to shift them back into unemployment just so they can cut their benefits. This is unfair on the genuinely sick, who should not suffer a £25-a-week cut in benefit."

Conservative sources have accepted that the plan to cut benefits for so many people would be slammed as harsh, but they stressed that the party was not targeting those who were genuinely unable to work. They acknowledged that it would have the impact of increasing the unemployment claimant total, but said that the party had long believed some incapacity benefit (IB) recipients were genuinely able to work and should therefore count as unemployed.

Under a Tory government, all 2.6 million recipients of IB would be assessed to see whether they are able to work.

The plans, which are certain to go down well with Tory activists, have been drawn up for the Tories by Lord Freud, a former adviser to the current Government who defected to Mr Cameron last year.

Lord Freud admits privately that there are similarities between the parties’ approaches. Labour, too, is committed to reducing IB and using private companies to help the long-term unemployed into work or training.

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