Downing Street has dismissed as groundless lawyers' claims that Prime Minister Mr Tony Blair and Foreign Secretary Mr Jack Straw are guilty of war crimes because of their roles in the Iraqi war.
The allegations were contained in a complaint the Athens Bar Association plans to file with the International Criminal Court.
The group says it is considering similar action against Spanish Prime Minister Jose Maria Aznar, who also backed the US-led campaign.
The bar association cited the Mr Blair, Mr Straw and others for "crimes against humanity and war crimes", as well as violations of international law, human rights and a number of treaties.
In a statement, the group said it felt an ethical and juristic responsibility to seek action from the new International Criminal Court.
But a No 10 spokesman responded: "As we have made clear on a number of occasions, the British Government has acted in accordance with international law."
The association's document excluded the US - which has challenged the court's jurisdiction over Americans.
The court, inaugurated in March and backed by both Spain and the Britain, is charged with intervening only when a country is unable or lacks the political will to carry out a trial.
Nato member Greece saw many anti-war protests during the conflict. The governing Socialists openly backed the demonstrations, but permitted US forces to continue using a base on Crete.
PA