Sir Menzies Campbell put "fair" taxation at the heart of his bid to lead the Liberal Democrats towards government today - pledging the party would not seek any extra cash from voters.
In a speech seen as a crucial chance for the new leader to cast off doubts over his style, he presented the Lib Dems as the only party offering the "politics of substance".
But he failed to make any reference to predecessor Charles Kennedy - forced out after admitting a drink problem just months after leading the party to its best general election result for 80 years.
Aides dismissed any suggestion of a snub - insisting Sir Menzies had been fulsome in his praise for Mr Kennedy's comeback speech on Tuesday and was keen to see him return to the frontline.
Sir Menzies' arrival on stage was accompanied by a thumping soundtrack and a series of images of his life outside politics - as an Olympic athlete, lawyer and campaigner.
He attacked the legacy of nine years of Labour government, dubbed David Cameron's Tories a "substance-free zone" and said his party had to show it was the "party of opportunity".
But at the centre of his message was a radical new tax package approved by delegates on Tuesday despite a potentially highly damaging revolt over dropping the 50p rate on high earners.
Instead, the party wants to slap far higher tariffs on the assets and pensions of the super-rich and impose massively higher "green" taxes to pay for income tax cuts for most workers.
Critics claim the tax package - which could see up to 90% of people pay less tax overall - is too complicated and will confuse voters who liked the old 50p top rate.
But Sir Menzies insisted the message was very simple: "Income tax cuts for hard-working people; the polluter paying the price; taxing wealth not work.
"Now this is the politics of substance; it's fairness in action; it's environmentalism in action; it's liberalism in action.
He underlined that - for the first time in its history - the party was not looking to up the amount of tax being raised to pay for extra public services.
"We will not raise the overall level of taxation but we will reform the tax system so that it is fairer, simpler and greener."
Sir Menzies made no mention of the turbulent events that surrounded Mr Kennedy's departure, including a leadership campaign hit by a series of personal scandals.
But a party source said: "Ming led the standing ovation for Charles Kennedy, praised his speech, praised him as a great electoral asset for the party.
"This speech is about what the Liberal Democrat agenda is, what the package is that we've got to sell to the electorate.
"You cannot possibly criticise Ming Campbell for not having been very generous in his words to Charles and his support for Charles."
Another former leader Lord Paddy Ashdown claimed yesterday that Mr Kennedy had refused the offer of a public handshake with his successor and ruled out his chances of regaining the leadership.
Sir Menzies said his was the only major party prepared to be open about its tax plans - and honest about the impact they would have.
More than two million of the lowest earners would stop paying income tax at all, he pointed out, the basic rate would drop to 20p and higher rate only affect salaries over £50,000.
"We'll take over two million of our lowest earners out of income tax altogether. More than two million people.
"Money back in the pockets of the poorest working families.
"We will reward ambition and aspiration - not penalise effort."
Some people would have to pay more, he said, insisting the party would not hide that.
"Those who can afford to make a greater contribution should do so," he said.
And everyone in the country would have to pay more if they were not prepared to change their behaviour to save the planet from global warming, he said.
"Yes, it means taxing aviation properly. Yes, it means fuel duty going up with inflation.
"And yes, it means paying more for the cars that pollute the most.
"If we are serious about the environment, only action will suffice."
Labour had squandered the chance to change Britain since 1997, he said.
"After three election victories, Labour has failed.
"The gap between rich and poor is wider than at any point under Margaret Thatcher. We have higher taxes, but little improvement in public services.
"Millions of pensioners remain consigned to poverty: two thirds of them women. Hard-working families are crippled by debt.
"Carbon emissions are rising. And now hospital wards are closing, doctors and nurses are losing their jobs.
"This is the domestic legacy of the Blair-Brown Government."
In a swipe at his Tory counterpart, he called on Mr Cameron to make a double apology - for backing the Iraq war and for his part in writing the last Conservative manifesto.
"Now Mr Cameron expresses his reservations about Britain's foreign policy. Well I say to that: where were you when what was needed was not reservation but votes?
"You, Mr Cameron, were in the government lobby backing military action against Iraq. You should apologise for supporting that war.
"And while you're at it, Mr Cameron, you should apologise for the last Tory manifesto, which you wrote - one of the most reactionary, unpleasant, right-wing manifestos of modern times."
He dismissed Mr Cameron's claim to be a liberal, adding: "Real liberalism means leading public opinion not following it.
"The British public is entitled to the politics of substance, not the politics of spin."
Sticking to domestic politics - an area where he has been perceived as weaker than in the foreign affairs brief where he made his reputation - he vowed to stand up for civil liberties.
"Labour has put our civil liberties under threat. Terrorism thrives where civil liberties are denied," he warned.
The Liberal Democrats would fight any moves to revive plans - thrown out by MPs - to allow terror suspects to be held for up to 90 days, he said.
Sir Menzies hailed the party's recent by-election results but said the chance was there to get the public to "vote for us in greater numbers still.
"But only if we show that we practise the politics of substance, just as we did in that great tax debate on Tuesday.
"And only if we show that we are the party of opportunity.
"That freedom, fairness and a commitment to the environment are at the very heart of everything we say - and everything we do."
He played on his own family history - born in a Glasgow tenement but helped to make a success of himself by dedicated parents - to reinforce the message.
"They saw to it that I got the chances they did not. But opportunity should not be an accident of birth. It must be open to everyone in Britain."
Sir Menzies has been keen to dispel a "posh" tag.
"My education was paid by for by the state, the sports facilities where I trained as an athlete were paid for by the state - and the health care that I have received was paid for by the state.
"So I know the true value of public services."
Calling for a halt to "permanent reform", he said public services had to be made more local - with fewer decisions made in Whitehall - and tailored to the needs of the individual.
He said that despite the recent turmoil and this week's controversy over the 50p tax rate, the party was "clear and united in our vision".
"My objective is nothing less than to complete the transformation of the Liberal Democrats from a party of opposition into a party of government.
"We must make the tough decisions necessary to show that we are radical and responsible.
"I have had three great opportunities in my life: in sport; in the law; and in politics.
"And now I have been given one more: the opportunity to lead our party from opposition towards government.
"And when that moment comes, to ensure that we are ready to build a Britain that is free, fair and green.
"That is my vision, your challenge, our future."
Sir Menzies also gave a determined message that it was time for the party to move on.
"You know, some people yearn for the years gone by; some mourn for what is past. But not me.
"I hunger for what is to come - for what is possible.
"We should have no fear of the future. Rather, we should relish the challenges ahead."
The selection of images of Sir Menzies down the years were shown to the hall to the strains of From On High - a tune that has become a theme of his leadership.
Shaking hands with party members as he made his way to the stage, he raised his arms in triumph as the hall applauded his arrival at the microphone.