David Cameron appealed for voters to free themselves from the "dark depression" of Gordon Brown yesterday night as he sought to get the Tories' election campaign back on track.
Amid more evidence that his poll advantage is evaporating, Mr Cameron admitted his party faced a "real fight" to win power and the outcome would be "close".
But he insisted that only the Tories had the radical economic and social policies to guide the country to the "bright light" at the end of the tunnel it was currently in.
The plea came in an impassioned 40-minute speech to the party's pre-election spring conference in Brighton, delivered without notes.
Painting the forthcoming battle as a choice between himself and Mr Brown, Mr Cameron launched an excoriating personal assault on the Prime Minister's "bossiness" and inflated ego.
"What sort of genius is it that doubles the national debt? What sort of genius is it that takes one of the best pension systems in the world and wrecks it?" he said.
"That's not genius, that's incompetence and at this coming election we are going to out your record, and tear it apart piece by piece."
Mr Cameron insisted the public knew that another five years of Mr Brown would be a "disaster", and warned that tensions between ministers were "dragging the country down". "Another five years of spending and bloat and waste and debt and taxes," he said.
"Another five years of failing to get to grips with our big social problems, another five years and the politics of that big top-down, bossy 'I know best' sort of approach and another five years of a government that is so dysfunctional, so divided, so weak.
"You have got a bunch of ministers that can't work with him but can't get rid of him, you have got a Prime Minister who can't work with them and can't make his government work.
"They are just locked in this dangerous dance of death that is dragging our whole country down and it is only the Conservative Party that can give people the hope of a different future."
The Conservatives had a "patriotic duty" to win the election so they could put the country on the path to recovery, according to Mr Cameron.
He said: "I want you to think of the incredible dark depression of another five years of Gordon Brown and say: 'No. No we are not going to do that'."
The Tory leader tempered his damning assessment of the economic "deep hole" the UK was in by stressing his "optimism" about its future prospects.
"With all our difficulties and the deficit and the debt and the social problems and the political system that has gone so wrong, it can feel like we are looking down some dark tunnel," he said. "But there is a bright light at the end of it."
He said the Tories would create an environment where business could thrive, reform welfare so people got a "hand up rather than a handout", create schools that gave genuine opportunity to all, and cut the costs of politics.
He also pledged to make the country more "family friendly" than ever before, and surprised many by stating that the Tory election manifesto would include details of controversial plans for recognising marriage in the tax system.
"We have got to inspire people with the potential of what we can be in this country and how optimistic we are that if we take the country on this journey we can achieve it," Mr Cameron added.
The Conservative leader sought to reassure activists who have become increasingly nervous at his failure to "seal the deal" with the electorate, despite Britain suffering the worst recession in 60 years and fierce bouts of Labour infighting.
Those fears were heightened yesterday when research by YouGov for the Sunday Times put the gap between the main parties on just two per cent - the smallest for more than two years.
If repeated at the general election - expected on or before May 6 - the results would be likely to leave Labour as the largest party.