Vladimir Putin accused President Bush tonight of orchestrating the war in Georgia in a plot to get John McCain elected to the White House.

In his most explosive allegation since the South Ossetia crisis erupted, the Russian Prime Minister said that the United States had provoked the conflict to aid the Republican candidate, who is an outspoken critic of the Kremlin.

“It is not just that the American side could not restrain the Georgian leadership from this criminal act. The American side in effect armed and trained the Georgian army,” Mr Putin said.

“Why spend years holding difficult negotiations and looking for complicated compromises in ethnic conflicts? It’s easier to arm one of the parties and push it to kill the other party, and the job is done.

“The suspicion arises that someone in the United States especially created this conflict with the aim of making the situation more tense and creating a competitive advantage for one of the candidates fighting for the post of US President.”

Mr Putin said that his defence officials had told him that Americans were operating in the conflict zone in Georgia during the fighting.

He added: “It should be admitted that they would do so only following direct orders from their leaders. Therefore, they were acting in implementing those orders, doing as they were ordered, and the only one who can give such orders is their leader.”

Mr Putin did not name Mr Bush directly but the White House swiftly denounced his allegations, made during an interview with CNN. His comments were also broadcast on Russian television, which had been circulating a similar conspiracy theory last week.

By lending his authority to the claims, Mr Putin has raised tensions with the US to a new level just days before Dick Cheney, the US Vice President, is due to arrive in Georgia to show support for its pro-Western leader Mikheil Saakashvili.

Dana Perino, a White House spokeswoman, said: “To suggest that the United States orchestrated this on behalf of a political candidate – it sounds not rational.

“Those claims first and foremost are patently false, but it also sounds like his defence officials who said they believed this to be true are giving him really bad advice.”

The deputy head of Russia’s general staff told reporters in Moscow that troops had found a US passport in a village near the South Ossetian capital of Tskhinvali, where he said Georgian special forces had been operating during the conflict.

“What was that gentleman’s purpose of being among the special forces and what he is doing today, I so far cannot answer,” Colonel-General Anatoly Nogovitsyn said.

“We have been looking for the holder of the passport but haven’t been able to find him. We know that he is a resident in the state of Texas.”

Mr Putin’s allegations were broadcast as President Dmitri Medvedev turned his back on a wave of Western condemnation and sought support in the East for his decision on Tuesday to recognise the independence of Abkhazia and South Ossetia from Georgia.

But China and the leaders of Kazakhstan, Tajikistan, Uzbekistan and Kyrgyzstan refused to rally round their fellow member Russia at a summit of the Shanghai Cooperation Organisation, despite an appeal from Mr Medvedev to denounce Georgian “aggression”.

A joint declaration praised Moscow’s “active role in promoting peace” in the Caucasus but also stressed the need to respect existing borders. It said: “The participants...underscore the need for respect of the historical and cultural traditions of each country and each people, and for efforts aimed at preserving the unity of the state and its territorial integrity.”

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