Turkish members of parliament spent Tuesday making their case to members of the committee that will consider the resolution.

"I have been trying to warn the lawmakers not to make a historic mistake," Egemen Bagis, a foreign policy adviser to Recep Tayyip Erdogan, the Turkish prime minister, said.

Up to 1.5 million Armenians are believed to have been killed in 1915-1917 as the Ottoman empire collapsed.

But Turkey says the death toll has been inflated and that the Armenians were victims of a civil war and internal unrest.

Demonstrations feared

The US embassy in the Turkish capital, Ankara, has warned Americans that the resolution could prompt protests in Turkey where, opinion polls say, anti-Americanism is already strong due to the Iraq war.

"There could be a reaction in the form of demonstrations and other manifestations of anti-Americanism throughout Turkey," the embassy said in a statement.

Gul said the resolution would cause "serious
troubles" with the US [File: AFP]
 
There are also concerns that a public backlash in Turkey could lead to restrictions on crucial supply routes through Turkey to Iraq and Afghanistan, and the closure of Incirlik, a strategic air base used by the US air force.

"Let us not forget that 75 per cent of all supplies to your troops in Iraq go through Turkey," Bagis said.

After France voted last year to make it crime to deny that the Armenian killings were genocide, the Turkish government ended military ties with Paris.

Some analysts have said that the anger created by the genocide declaration could make it hard for the Turkish government to resist public calls to cross into Iraq in pursuit of Kurdish separatists.

Ankara said on Tuesday that it was preparing for raids into northern Iraq as it was willing to use all necessary measures against fighters from the PKK group.

"If the Armenian genocide resolution passes, then I think that the possibility of a cross-border operation is very high," Ihsan Dagi, a professor of international relations at Middle East Technical University in Ankara, said.

'Unique opportunity'

Armenian groups in the US have been rallying the large diaspora community to push for a succesful committee vote so the bill can be discussed in the full House.

On Tuesday, Bryan Ardouny, executive director of the Armenian Assembly of America, wrote to Tom Lantos, the committee's Democratic chairman and Ileana Ros-Lehtinen, its leading Republican member.

"We have a unique opportunity in this congress, while there are still survivors of the Armenian genocide living among us, to irrevocably and unequivocally reaffirm this fact of history," he said.

Catholicos Karekin II, the head of the Armenian Apostolic Church, will give the opening invocation to the House's session ahead of the vote.