Ed Miliband has insisted that Labour is the "only alternative" to the coalition Government as he joined his by-election campaigners in Eastleigh.
The opposition leader was joined by about 50 supporters waving placards as he promoted his plans for a "mansion tax" and to introduce a 10p tax rate.
He also gave his backing to his by-election candidate, best-selling author and satirist John O'Farrell. The Hampshire town is the focus of a fierce battle between the main parties, with the Lib Dems keen to prevent their Tory coalition partners snatching the seat.
Labour is hoping for a good showing in the vote on February 28, which became vacant with the resignation in disgrace of ex-cabinet minister Chris Huhne after he admitted dodging a speeding penalty.
Mr Miliband spoke of his announcement that Labour favoured reviving the 10p income tax rate. Labour says that could be paid for by a levy on two million-plus homes - a policy promised in the last Liberal Democrat manifesto but opposed by the Conservatives.
The party hopes to put the "mansion tax" proposals to a vote either before the Budget in an opposition day debate or through an amendment to the Budget-implementing Finance Bill.
He said: "This is a living standards by-election, that's the issue on the minds of so many people in Eastleigh - not being able to afford the weekly food bill, not being able to afford to fill up the car."
He said that the Government was in favour of a tax cut for those earning more than £1 million.
"If you want that you can vote for the Lib Dems or Tories, if you want an alternative you can vote for Labour," Mr Miliband said. He also questioned whether Nick Clegg's party would continue their previous support for a mansion tax.
"They claim to be in favour of a mansion tax as they used to be against tuition fees, and they broke that promise."