The leader of one of Britain's most important political parties said on Tuesday that the "special relationship" between Britain and the United States was a relic of a bygone age and needed reassessing.

The Liberal Democrat leader Nick Clegg, who has been the star so far of the campaign in the run-up to the general election on May 6, told a press briefing in central London, "There have been very profound differences between ourselves and the Americans, particularly at the height of the George Bush-Dick Cheney orchestrated war on terror.

"There were a number of things alleged to have occurred -- torture, extradition, flagrant disregard for the most basic standards of conduct in conflict, in interrogation of those detained, which flatly contradicted the most basic values on which this nation is founded -- the rule of law, fairness, human rights. "

Clegg, whose party has been the third and sometimes tiny force in British politics for 90 years, was speaking after a remarkable week for himself and his party. A live TV debate last week between the leaders of the three largest parties in the British election campaign thrust him onto the national stage and made him an overnight sensation.

Clegg's personal ratings improved dramatically and so did those of his party, which moved up in some polls to parity with the ruling Labor party and the main opposition Conservative party to create a three-horse race.

Clegg's party could win the election, and in the event of a hung parliament (one in which no party has a majority of Members of Parliament) he could play a key role in forming a governing coalition.

He was critical of the "special relationship" between Britain and America and said it was time to move on from a British foreign policy stance formed in 1956 after the Suez Crisis, in which the unwillingness of the United States to back Britain, France and Israel in their seizure of Egypt's Suez Canal led to a humiliating climb down and withdrawal by the three powers.

"The conventional wisdom since the Suez Crisis, and this is something the political establishment either Labor or Conservatives has stuck to religiously, is that the linchpin around which British foreign policy should be organized is the Atlantic relationship between the United Kingdom and the United States," he said.

"If we want to prepare ourselves for the future and not be imprisoned by the past we are going to have to release ourselves from this spell that says default Atlanticism should guide everything we do in the world."

The Cold War was the glue which had held the relationship together said Clegg, and Britain and America had been "joined at the hip in that conflict, but those days are past."

Clegg said the American viewpoint had changed as well under president, and now the U.S. position was that "it's a good relationship but it is not the special relationship around which we organize our world view."

"If they are moving on, why on earth aren't we?" said Clegg.

Strategy in the war in Afghanistan had been wrong until last year, said Clegg, there had been "no political strategy, no coordination of international efforts, no attempt to tackle corruption in Kabul, and no attempt to divide the Taliban by negotiation."

He said he supported the war as the reasons to be there were all good reasons, "but either do the job properly or don't do the job at all."

Clegg said his party opposed the like-for-like replacement of Britain's independent, strategic nuclear deterrent, the Trident submarine fleet because it was a hangover from the Cold War and the strategic threats were now terrorists and not the Soviet Union.

"The world is changing it has changed, in politics you either change with it or remain a prisoner of the past," said Clegg.

Clegg and the two other major party leaders, Conservative David Cameron and Labor Prime Minister Gordon Brown, on Thursday are set for the second of three live TV debates. They are set to debate foreign policy for 90 minutes in front of a TV audience who will question the leaders.

The pressure is high for all three leaders. Cameron has a reputation as a good communicator and must make a gain in his party's popularity if they are to have a chance of forming a majority government after the May 6 election.

Brown is perceived as dour and was held by many viewers to be the loser of the first TV debate, and he will be seeking to turn that around on Thursday.

For Clegg, the challenge is to keep the support he spectacularly picked up last week.