Armenian orphans in Constantinople, now known as Istanbul, board a ship bound for Greece. The ship was laid on during World War One by Near East Relief, an American charity.

ANKARA: One of the worst massacres of the 20th-century came back to haunt international politics yesterday when a powerful Washington panel voted to call the murder of about 1.5 million Armenians in Turkey “genocide”.

After more than three hours of debate, the House Committee on Foreign Affairs narrowly approved a resolution calling on President Obama to “characterise the systematic and deliberate annihilation of 1.5 million Armenians as genocide”.

The vote went ahead despite last-minute pleas from the White House and State Department and triggered a furious reaction from Recep Tayyip Erdogan, the Turkish Prime Minister.

“We condemn this resolution, which accuses the Turkish nation of a crime it did not committ,” he said. As Armenian observers applauded the vote on Capitol Hill, the Turkish Ambassador to Washington was recalled.

The Obama Administration may still be able to prevent a full vote in the House of Representatives but yesterday’s resolution threatened to poison America’s relations with its closest Muslim ally. Washington depends on Turkey for access to northern Iraq and in its regional efforts to isolate Iran.

The vote, with 23 congressmen in favour and 22 against, will also jeopardise historic efforts begun last year to create normal diplomatic relations between Turkey and Armenia.

“We are seriously concerned that this resolution approved by the committee despite all our warnings will harm Turkey-US ties and efforts to nomalise Turkey-Armenia relations,” Mr Erdogan added.

Mr Obama promised as a candidate to break with longstanding US practice and start calling the First World War era killings genocide if elected to the White House. He broke the promise last year, refusing to use the word on a visit to Ankara, where he praised Turkey as a model Muslim democracy.

He telephoned his Turkish counterpart this week to thank him for working towards a rapprochement with Armenia, while Hillary Clinton, the Secretary of State, had implored the Foreign Affairs Committee not to go ahead with the vote.

The committee chairman, Howard Berman, refused to be swayed. At the start of yesterday’s hearing he called Turkey a vital and usually loyal ally but insisted that nothing justified “turning a blind eye to the reality of the Armenian genocide”.

Mr Berman, a California Democrat who counts powerful Armenian émigrés among his Los Angeles constituents, said that Turkey’s duty to face up to its past compared to that of Germany to face up to the Holocaust and South Africa to acknowledge the full horror of apartheid.

Ankara accepts that many thousands of Christian Armenians living in what was then eastern Anatolia died in blood-letting by Muslim Ottoman troops in 1915. It rejects the term “genocide” and says that the 1.5 million figure for the final death toll is exaggerated. Experts, including some of Turkey’s own most respected historians, disagree.

Taner Akcam, a professor at Clark University in Massachusetts, became the first Turkish specialist to call the killings genocide in his comprehensive study A Shameful Act, published in English three years ago.

Since then Turkish and Armenian leaders have begun a normalisation process that has included a football match in Turkey between the two countries’ national teams last year, attended by the Armenian President.

The last time a resolution on the events of 1915 was debated in Congress it was approved by the House committee but never voted on by the full House of Representatives after Bush Administration officials urged congressional leaders not to table a vote for the sake of US-Turkish relations. Even so, Turkey temporarily withdrew its Ambassador to Washington.

In a sign of the power of historical consensus to yield concrete restitution, the French insurance giant AXA began making €8,000 (£7,200) payments yesterday to families of Armenian victims of the 1915 killings who bought policies from companies that AXA has since taken over.

France and Canada have classified the killings as genocide. Britain, like the US, has not.