Chancellor George Osborne has vowed to slash another £10bn from the benefits budget as he insisted he would "finish the job" of rebuilding the economy.
The Chancellor, speaking at the Tory party conference, was bullish as he defended his record in Government and declared that the Tories should be "proud" of the tough action taken.
Mr Osborne told delegates the economy is now "healing" but admitted Britain faced further austerity because the crisis had been worse than feared.
He also sought to seize back the One Nation slogan from Labour leader Ed Miliband by arguing that the Tories are the true party of "one nation working together".
Outlining his intention to slash the welfare budget further on top of the £18bn in cuts already in motion, he suggested jobless parents with large families could be targeted.
And he prompted anger by indicating that under-25s currently on housing benefits rather than living at home with their parents could lose the financial support.
"How can we justify the incomes of those out of work rising faster than the incomes of those in work?," he asked.
"How can we justify giving flats to young people who have never worked, when working people twice their age are still living with their parents because they can't afford their first home?
"How can we justify a system where people in work have to consider the full financial costs of having another child, whilst those who are out of work don't?"
Mr Osborne also defended the move to slash the top rate of tax, insisting the 50p rate had been "cripplingly uncompetitive", raised no money and cost jobs.
And despite his Lib Dem partners insisting they would not sign up to further welfare cuts without a new levy on the rich, he also ruled out a wealth tax or a mansion tax.
"I am not prepared to contemplate things that make no economic sense and destroy jobs... our future lies as a country where wealth creation is not something to be penalised - but encouraged," he said.
"Our entire economic strategy is an enterprise strategy. We will be the government for people who aspire."
His stance puts him on an immediate collision course with the Lib Dems and sets the stage for bitter coalition infighting ahead of the autumn statement in December.
Shortly before the Chancellor's speech, Deputy Prime Minister Nick Clegg said: "Nothing in detail has been agreed on further cuts and savings to welfare.
"The Conservatives are entirely entitled to set out their stall about what we do as a country as we have to tighten our belts further.
"My attitude has always been very simple, very straightforward: that as we have to make more savings as a country, you start at the top and work your way down not other way around.
"These are the kind of things that we will thrash out in Government in the months ahead."
The address in Birmingham contained new plans to let workers buy shares in the firms they work for in return for dropping unfair dismissal, redundancy and flexible working rights.
Employees would receive 2,000 to 50,000 shares that would be exempt from capital gains tax when sold.
Dismissing the possibility of an economic Plan B, Mr Osborne insisted: "We made a promise to the British people that we would repair our badly broken economy.
"That promise is being fulfilled. The deficit is down by a quarter. There are one million more private sector jobs. The economy is healing.
"That healing is taking longer than we hoped, because the damage was greater than we feared but let the message from this conference be clear: we will finish the job we have started."
He insisted his catchphrase "we're all in this together" was more than just a slogan and still applies today, promising that future austerity would hit the richest hardest.
He admitted that the Tories had probably "paid a price" for being candid about the huge economic challenges but insisted there had been no alternative.
Mr Osborne dismissed Mr Miliband's attempts to take on the "One Nation" mantle in his conference speech as "risible" and attacked him for failing to mention the deficit.
He insisted the "modern Conservatives" represent corner shop workers, teachers, commuters, pensioners and entrepreneurs.
"They are all part of one nation - one nation working together to get on. That is the nation we represent. These are the people I serve as Chancellor," he said.
He added: "To the people of Britain I say this. Whoever you are, wherever you come from, if you're working for a better future - we are on your side."
Mr Osborne asked for the party's "trust" and "resolve" as he issued a stark warning about the huge challenges ahead.
"It isn't too much to say that the future prosperity of our country, the future of a free enterprise system under law, even the stability of Europe (Chicago Options: ^REURUSD - news) , is in question in a way it has not been in my lifetime," he said.
"I cannot pledge to you simple answers or a quick solution. This year has shown we are a country confronted on all sides by great difficulties.
"But this year has also shown we live in a country of courage and creativity. A country that can do incredible things and succeed when we pull together."
The address in Birmingham followed a Sky News poll by Ipsos Mori showing just 27% of people are satisfied with the Chancellor's performance - his lowest ever personal rating.
Meanwhile, London Mayor Boris Johnson was greeted by passers-by chanting "Boris! Boris!" as he arrived at the conference to address a fringe event later organised by the Conservative Home website called Re-elected and Olympotastic, and to deliver a keynote speech on Tuesday.
Mr Johnson has been touted as a possible alternative to David Cameron as Conservative leader.
Asked if he was in Birmingham to make trouble for Mr Cameron, Mr Johnson replied: "I'm here to support the party."
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