Gordon Brown today denied electioneering over the Pre-Budget Report, saying that benefits and pensions would continue to rise.
Speaking on a visit to King's College Hospital in south London, the Prime Minister said the Government was doing its "duty".
Asked about accusations of electioneering, he said: "Benefits will continue to go up, child benefit and child tax credit, pensions will continue to go up.
"It's our duty to those people who have served the country all their lives and we are doing our duty."
The Prime Minister hit back after the Conservatives accused Chancellor Alistair Darling of a "pre-election con" in yesterday's mini-Budget.
Mr Darling announced a 1.5% rise in child benefit and disability benefits which are linked to inflation, due to come into effect next April - just weeks ahead of the expected date of the general election.
He announced he was overriding the normal requirement to link the rise to the rate of inflation the previous September, as this would have led to the benefits being frozen because inflation was negative at that point. But he made no announcement on whether the rise could be sustained after April 2011.
Shadow Chancellor George Osborne said the figures showed no money had been set aside to pay for benefit hikes to be continued for more than one year.
"We have got to stop having a pre-election con where you put benefits up weeks before a general election and cut them afterwards," he told the BBC Radio 4 Today programme.
But Mr Darling also denied "electioneering" with the rise, insisting that the benefits would be reviewed again in 12 months' time and the extra cash will not be taken back.
"A 1.5% increase in benefits, I don't think, can, with the best will in the world, be called electioneering. It is not a temporary rise, it is a rise we have put in this year and it is not going to be taken back. We will look at it again next year."
He went on: "Every year the Government has to have a review of benefits. In 12 months' time we will look at what the situation is and we will know what inflation is in 12 months. The announcement I made yesterday in relation to those particular benefits was for this year.
"I was quite deliberately bringing the thing forward, because otherwise you would have had a situation where these benefits were frozen and I thought that would be a little bit unfair."
Mike Brewer, of the independent Institute for Fiscal Studies, claimed the effect of Mr Darling's PBR was that the 1.5% benefit rise would be only temporary.
"The 1.5% rise, costing £700 million, is set to be only temporary, as the Chancellor committed himself - or rather, his successor - to increase these same benefits by 1.5% less than inflation this time next year," said Mr Brewer.
Liberal Democrat work and pensions spokesman Steve Webb said the Government had given "conflicting" comments on the issue.
"If ministers can't get their heads around this complicated stitch-up then what hope do people claiming these benefits have?" he asked.
"Alistair Darling appears to have hoodwinked those listening to his Pre-Budget Report about what this could mean for people with disabilities and families in the long run. But, incredibly, he also seems to have misled his own colleagues.
"The Government needs to get its facts straight. This ruse will mean a real-terms cut in benefits for children and people with disabilities in 2011 and all ministers must take responsibility for this."