David Cameron today called on Britons to "pull together" to get the country's economy back on track, promising that within a few years the sacrifices they make will deliver financial rewards.
And he urged all citizens to get involved in action to improve their communities and build a "Big Society", telling them: "Your country needs you."
In his first speech to a Conservative conference as Prime Minister, Mr Cameron acknowledged that there was "anxiety" over the massive public spending cuts due to be imposed in George Osborne's spending review on October 20 and recognised that it was not easy for families to cope with the loss of Child Benefit announced this week.
But he dismissed Labour's argument that the UK's record £109 billion deficit should be paid off more slowly in order to protect jobs, telling the gathering: "There is no other responsible way."
Mr Cameron vowed that the cuts would be "fair" and that the Government would protect the sick, vulnerable and elderly as it sought to eliminate the structural deficit within five years.
And he said: "I promise you that if we pull together to deal with these debts today, then just a few years down the line the rewards will be felt by everyone in our country.
"More money in your pocket. More investment in our businesses. Growing industries, better jobs, stronger prospects for our young people. And the thing you can't measure but you just know it when you see it - the sense that our great country is moving ahead once more."
Senior party sources played down suggestions that Mr Cameron was hinting at tax cuts to come before the 2015 general election, once the programme of economic retrenchment has taken effect. They insisted he was referring to the financial benefits to be reaped from renewed growth, enterprise and the creation of new businesses.
Mr Cameron's speech rounded off a conference in Birmingham which has been dominated by Mr Osborne's announcement on Monday that Child Benefit was to be abolished for higher-rate taxpayers. The PM was last night forced into a TV apology for failing to be upfront with voters about the need for the cut, which will cost three-child families with a parent earning over £44,000 around £2,500 a year from 2013.
But he mentioned the furore only in passing, telling activists: "As we work to balance the budget, fairness includes asking those on higher incomes to shoulder more of the burden than those on lower incomes.
"I'm not saying this is going to be easy, as we've seen with child benefit this week. But it's fair that those with broader shoulders should bear a greater load."
Mr Cameron said: "I know how anxious people are.
"'Yes', they say, 'of course we need to cut spending. But do we have to cut now and by this much? Isn't there another way?'
"I wish there was another way. I wish there was an easier way. But I tell you: there is no other responsible way."
He denounced Labour's economic policies as "selfish and irresponsible", warning that delaying debt repayment would pile the burden of increased interest rates and spending cuts on to future generations.
In a message to Ed Miliband's party, he said: "You want us to spend more money on ourselves today, to keep racking up the bills today, and leave it to our children - the ones who had nothing to do with this - to pay our debts tomorrow.
"That is selfish and irresponsible.
"I tell you what: these Labour politicians who nearly bankrupted our country, who left a legacy of debts and cuts, who are still in denial about the disaster they created, they must not be allowed anywhere near our economy ever, ever again."
But shadow health secretary Andy Burnham accused Mr Cameron of "rewriting history".
"Great pains have been taken by David Cameron and other speakers to say it was all about the decisions that Labour took," Mr Burnham told the BBC. "Well I'm afraid that's not right. Governments all over the world are facing up now to the aftermath to the economic crisis. It didn't begin here Mr Cameron - it began in the USA."
And TUC general secretary Brendan Barber warned that deep and rapid cuts to state spending would hit the vulnerable and undermine economic growth.
"The language and social tolerance may be different, but the economic policy is as 80s as shoulder pads and big hair," said Mr Barber.
David Frost, director general of the British Chambers of Commerce, said firms would welcome the PM's commitments to "get behind wealth creators".
Less than a fortnight ahead of the Strategic Defence and Security Review which is likely to pave the way for 10% cuts in the defence budget, Mr Cameron vowed he would "take no risks with Britain's security" and would "always" keep the UK's nuclear deterrent.
He dismissed Labour claims that his Big Society agenda was simply a cover for spending cuts, insisting it was about building "a nation of doers and go-getters, where people step forward not sit back, where people come together to make life better".
The "beating, radical heart" of the Government was shifting power away from the centre to ordinary people, allowing them to get involved in running and shaping local services in their communities.
"When we say 'we are all in this together', that is not a cry for help but a call to arms," said Mr Cameron.
"Society is not a spectator sport. This is your country. It's time to believe it. It's time to step up and own it."
He pledged to deliver Government support to "the doers and grafters, the inventors and the entrepreneurs" who he said would provide the drive to get Britain's economy going again.
Just months after becoming the first Conservative Prime Minister in 13 years and the first since the Second World War to lead a coalition administration, Mr Cameron made a point of reassuring the party faithful about his partnership with Liberal Democrats.
He won applause with a tribute to party darling Margaret Thatcher as "the greatest peacetime Prime Minister of the 20th century", and said he would be her host at a celebration of her 85th birthday at 10 Downing Street next week.
But he defended his decision to go into coalition with Nick Clegg's Lib Dems rather than seeking to form a minority administration, saying the country wanted "leadership not partisanship".
"At its best, this party always puts country first," he said.
"We'll leave the vested interests to others. This is the party of the national interest and with this coalition that's what we're showing today."