Gordon Brown, reeling from a drubbing in local polls, sought to allay voters' concerns over the economy on Wednesday in the face of taunts from an opposition that can smell victory at the next general election.
Brown, appearing in parliament for the first time since Labour suffered its worst local election result on record, said the Conservatives lacked substance and would jeopardise hard-won stability.
But Conservative leader David Cameron - on track to win a landslide if last Thursday's poll result were to be repeated in a general election due by 2010 - said Brown had run out of ideas, had no vision and was full of empty words.
"The choice in the country is between a government that has created jobs, stability and growth and a Conservative Party that has got absolutely nothing to offer the people of this country," Brown said in his weekly parliamentary joust with Cameron.
He accused the Conservatives of nothing more than "slick salesmanship".
Cameron retorted: "People expressed their view on the choice last week ... If he had a coherent vision, wouldn't people have heard it by now?"
The Conservatives won an estimated 44 percent of the vote in local council elections. Labour's share slumped to 24 percent and it lost the London mayoral post to the Conservatives.
The drubbing has sparked Labour mutterings about Brown's suitability to lead the party into the next general election although most MPs and ministers have been publicly loyal.
However, in an opinion poll by Populus for The Times on Wednesday, 55 percent of Labour voters said the party would be more likely to win the next election if Brown resigned "to make way for a younger, fresher, more charismatic alternative".
Brown plans a series of policy announcements in coming weeks and ministers are working on finding ways to compensate people who lost out from the scrapping of the 10p tax band.
MPs said the tax blunder was a key factor in the election as well as voters' concerns over rising food, energy and mortgage prices and fears of a property market slump.
"We've got a government that just lurches from one relaunch to another," Cameron said. "He's got nothing to sell and he's useless at selling it."
Labour faces another poll test next week in a by-election at Crewe and Nantwich in Cheshire.
The Conservatives are hoping to win the seat in what until now was a Labour stronghold.
Brown is also set to anger some Labour MPs when he pushes ahead with plans to extend the maximum time police can hold terrorism suspects to 42 days from 28 days.
