"The Prime Minister said that Egypt can not be included in the peace process as long as Azzam Azzam remains in prison for crimes he did not commit," Sharon spokesman Raanan Gissin told Agence France-Presse (AFP).

Azzam, an Israeli Arab, has been serving a life sentence of forced labor in Egypt since August 1997 when he was convicted of spying for Israel.

Successive Israeli governments have demanded his release but Egypt has consistently refused.

However, former director of Israel Affairs in the Egyptian Foreign Ministry told al-Jazeera Satellite Channel that “Israel is trying, by any means, to avoid implementing the peace roadmap with the Palestinians”.

“Sharon knows damn well that Egypt will not respond to such absurd blackmail. He just wants to waste time in meaningless hassle not to meet Israeli commitments provisioned for in the peace process,” the former Egyptian official added.

In Cairo, Egyptian Foreign Minister Ahmed Maher dismissed Sharon's comments as "worthless".

"Egypt's role is in no way linked to what Ariel Sharon might think or want. Our role is determined by geography, history and Egypt's importance" in the region, Maher said.

"There is no reason to pay any attention to his comments," Maher told reporters. "They are worthless."

On the question of Azzam, Maher said: "The courts have decided. Egypt is not prepared to discuss this matter with just anyone because it is solely a matter for the Egyptian justice system."

On a possible return of an Egyptian ambassador to Israel, he said: "That is a decision which concerns no-one but Egypt and will be taken in line with what President Hosni Mubarak judges to be in the interests of Egypt and peace."