Gordon Brown has used his new year message to warn voters not to let the Conservatives "wreck the recovery".
While it had been painful for some, his government had already "seen off the worst of the recession", the PM said.
With an election pending, he pledged a decade of "shared prosperity" and warned against unfairness if "the privileged few protect themselves".
The Conservatives said the message showed Mr Brown was "intent on waging a negative and pointless class war".
Mr Brown's new year message, delivered on the Downing Street website, also includes a reference to the alleged US plane bomb plot on Christmas Day.
He says it was a reminder that there was "a terrorist threat which puts our safety and security at risk" and pledges "no let-up" in efforts to stop attacks on Britain.
"This will have my relentless focus in 2010, just as Afghanistan will have," he said.
He promised plans to invest in the "industries of the future" - such as high speed rail and clean energy - as part of plans to "get Britain moving forward again".
But he also used the message to attack the Conservatives - who have maintained a lead over Labour in the polls all year - and draw what he sees as the dividing lines between the two parties.
BBC political correspondent Ross Hawkins
Gordon Brown does not name the Conservatives in his New Year message but you do not need to read his words too closely to spot attacks on the Tory leader David Cameron.
The prime minister says some are planning a decade of austerity and unfairness in which a privileged few will protect themselves. That is how he sees Tory plans.
The Conservatives say this adds up to a negative and pointless class war. For now though it is a key Labour attack line. Ministers are not talking about Mr Cameron's Eton education, but they are painting Conservative policy as biased towards the wealthy.
Whether that makes for a class war or not, we are going to hear much more of it as the general election approaches.
He pledged to create "fairly shared" prosperity - and contrasted that with those "who say we must plan for a decade of austerity and unfairness where the majority lose out while the privileged few protect themselves".
While he acknowledged it has been a difficult 18 months, he said that if the experience of the last recession - under a Conservative government - had been repeated, unemployment, repossessions and bankruptcies would have been much worse.
"The decisions taken by [Chancellor] Alistair Darling and all the ministers of this government have meant that we have already seen off the worst of the recession," he says.
"There is no denying it has been painful for some - and there are still tough times ahead," Mr Brown went on.
But he said that he was confident that unemployment would start to drop in 2010 and more small businesses would open.
"That wasn't inevitable; it was the change we chose. And so my message today is simple: Don't wreck the recovery."
'Go for growth'
He pledged to "reduce the deficit at a responsible pace, without choking off the recovery" and to "go for growth".
On Wednesday Justice Secretary Jack Straw, in an article for the Independent newspaper, wrote that only a "wealthy few" would benefit from Conservative tax plans and accused the party of planning "the most expensive election campaign in British political history".
"Never before in the history of British elections has a political party spent so much to help so few," he said.
Last week Cabinet Office Minister Tessa Jowell warned Mr Brown not to turn the general election campaign into a "hideous" class war, after he accused Conservative leader David Cameron of pursuing policies dreamt up "on the playing fields of Eton".
Shadow home secretary Chris Grayling said the prime minister's message was "backward-looking" and "shows that despite warnings from his own cabinet Gordon Brown remains intent on waging a negative and pointless class war".
He said: "Gordon Brown has spent money like there is no tomorrow yet the gap between rich and poor has grown wider than ever.
"This message sounds like the last throw of the dice from a government that has no idea how to solve Britain's problems."
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