Iain Duncan Smith has said that no one will be allowed to get in the way of his ambition to lead the Conservatives back into government.

In his keynote address to the party's rank-and-file in Blackpool, the Tory leader warned that Labour will win a third term of government unless wounds are healed.

"My mission is to take the Conservative Party back into government. I won't allow anything or anyone to get in my way," Duncan Smith said to applause and cheers.

But in an uncompromising performance, critics were told that splits and rows were damaging the party.

"I say to everyone here today: You either want my mission or you want Tony Blair. There is no third way," he said.

Amid continuing speculation about plots to oust him as leader, Duncan Smith told those who disagreed with his stance to "get on board or get out of our way".

During last year's address to the conference, the Tory leader described himself as the "quiet man" of British politics.

But this year saw a move away from that description.

In a speech which received a series of standing ovations he said: "The quiet man is here to stay and he's turning up the volume."

And Duncan Smith was outspoken in his criticism of the government.

He attacked Tony Blair's government - dismissing it as "double-dealing, deceitful, incompetent, shallow, inefficient, ineffective, corrupt, mendacious, fraudulent, shameful [and] lying".

He went on to brand Labour as the "most dishonest and incompetent government of modern times".

And lashing out at the prime minister, Duncan Smith said Blair had lied over his role in the death of government scientist Dr David Kelly.

"Immediately after Dr Kelly's death, Tony Blair said he had nothing to do with his public naming. That was a lie," he said to loud applause.

"Tony Blair chaired the meetings that made the fatal decisions. He is responsible. He should do the decent thing and he should resign."

And he warned his party that Labour would "play dirty" at the next general election.

"A prime minister that lies about his own record won't hesitate to lie about us," he said.

"A government machine willing to smear the Paddington train crash survivors and Dr Kelly won't think twice about smearing me.

"A political party prepared to use the tragedy of September 11 to bury bad news will do everything to can to hide the scale of its own failure."

Duncan Smith added: "Tony Blair is alright for the telly, but he is all wrong for the country."

The Conservative leader also took a swipe at the Liberal Democrats and the alleged drinking habits of leader Charles Kennedy.

"Gordon Brown is the biggest tax raiser in British history, but Charlie Kennedy wants to raise them even further," he said.

"Except on wines and spirits of course."

He also slammed the "utter madness" of the Lib Dems who opposed tougher sentences for serious criminals while wanting to give them the right to vote.

"They promise things they know they'll never have to deliver. They are not a fit party of government and we are going after them," Duncan Smith vowed.

And he went on to accuse the Liberal Democrats of "playing games" with the defence of Britain in their opposition to the war in Iraq.

Setting out the Conservative vision, Duncan Smith said he would be "tough on tax and tough on the causes of tax".

"We will always be a lower tax government than Labour. And yes, we plan to cut taxes," he added.

But the Conservative leader also vowed to reform public services and introduce greater choice.

"Choice in public services means peace of mind," he said.

"It means you won't be stuck with second rate services. It means there'll be an alternative school or hospital if you need it."

Duncan Smith, an ardent eurosceptic, also warned that the new European Union constitution was a threat to Britain's nationhood.

He said the Conservatives had scared the government off holding a referendum on joining the single currency.

"But we are now faced with an even graver danger, a threat to our very nationhood," he said.

"The euro would take away our power to decide our economic policy, but the European constitution would take away our power to decide who governs Britain."

Under the plans the UK would lose control of immigration and would "no longer be able to choose its allies", said Duncan Smith.

"Unelected commissioners would have the final say in almost every government department, affecting every aspect of our daily lives," he added.

The prime minister was giving away powers held in trust for the British people, said the Tory leader.

Pledging to fight for a referendum on the constitution, he told the party faithful: "We will fight in next year's vital European elections, we will fight in parliament, we will fight at the general election.

"And I promise you, I will fight, fight and fight again to save the country that I love."

Turning to the controversial issue of the war in Iraq, where the Conservatives strongly backed the government's commitment to military action, Duncan Smith defended his stance.

But he failed to mention weapons of mass destruction, and instead turned to the human rights argument favoured by Tony Blair over recent months.

"Everyone on Earth has the God-given right to live in a free country protected by the rule of law. That's one of the reasons why I supported the war in Iraq," he said.

"I know some say the war was wrong and I respect their opinion.

"But I believe the world is better off today because Saddam Hussein is no longer running Iraq."

Duncan Smith concluded the speech by setting out his personal values - stating why he is "proud to be a Conservative".

Stressing his commitment to helping people "who play by the rules", he said "we all have a special duty of care for the most vulnerable people in our country".

"Fundamental to my Conservatism is this double commitment. A belief in aspiration and a belief in security for all," he said.

"I am appalled at the waste of talent, the depth of untapped potential, within today's Britain."

And he warned that the public was increasingly despairing at the state of society.

"You can hear, steady as a heartbeat, the hurt and anger of the people of this country," he said.

"This Labour government cannot hear them above the racket of its own spin and the rattle of its own demise.

"But I've heard them, and I've heard their anger."

He warned that children were being mugged on the way home from school and patients were waiting in agony for operations.

"These are the people I am in politics for. These are the people who brought me here. These are the people who sustain me," he said.

"Every in Britain deserves a fair deal, we must be on their side.

"Our mission, our duty, is to bring them hope. To fight for them, to be strong for them, to be here for them.

"And together we must win for them."