President Obama was accused yesterday of being "timid and passive" in his response towards the turmoil in Iran where, Republicans claim, protesters are crying out for America to show moral leadership.

Although he used his strongest words yet over the weekend, when a written statement called on the Iranian Government to stop all violent and unjust actions against its own people, Mr Obama has so far declined to pronounce on the fairness of the election and is facing growing criticism at home.

Senator John McCain, who was defeated in America’s own presidential election last November, said yesterday that Mr Obama had still not gone far enough in offering support to the protests.

"It’s not just what takes place on the streets of Iran but what takes place in America’s conscience. We have to be on the right side of history," he said. "We just need to say that we’re on their side as they seek freedom."

Lindsey Graham, another Republican senator, contrasted Mr Obama’s cautious position with the tougher language coming from other world leaders such as Gordon Brown and Nicolas Sarkozy, saying: "The President of the United States is supposed to lead the free world, not follow it. He’s been timid and passive more than I would like."

The White House said that that Mr Obama wanted to avoid playing into the regime’s hands by allowing it to portray demonstrators as American stooges. It also wanted to avoid a confrontation that might wreck any prospects of negotiations with Tehran over its nuclear programme.

"He’s got a very delicate path to walk here," Chris Dodd, a Democratic Senator, said. "You don’t want to take ownership of this. The worst thing we could do at this moment for these reformers, these protesters, these courageous people in Tehran, is allow the Government there to claim that this is a US-led opposition, a US-led demonstration."

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