Mahmoud Abbas, the Palestinian leader, has warned of a "national disaster" if any of the 1,550 Palestinian prisoners on hunger strike in Israeli jails were to die.

Mr Abbas spoke as two of the hunger strikers, Bilal Diab and Thaer Halahla, entered their 75th day without eating, and after international rights groups and governments said they were concerned that prisoners could die if they continued to refuse food.

"The situation of the prisoners is extremely dangerous," Mr Abbas told a meeting of the Palestine Liberation Organisation´s executive committee.

"Some of them face real harm, and that would be a national disaster that no one can tolerate. I hope and pray to God that no one gets hurt because it would be a major disaster."

The committee called on all Palestinians to observe a one-day fast on Monday in solidarity with the prisoners.

In a letter, Tony Blair, the former Prime Minister and current envoy for the Middle East Quartet, urged Israel to "take all necessary measures to prevent a tragic outcome that could have serious implications for stability and security conditions on the ground."

Diab and Halahla are specifically protesting their jailing by Israeli authorities without charge under a procedure known as administrative detention.

The broader hunger strike by around 1,550 Palestinian prisoners is intended to pressure Israeli prison authorities to end the use of solitary confinement and ease a wide range of restrictions, including on family visits and prisoner education.

Hamas Deputy Chief Mussa Abu Marzuk said that following Egyptian intervention on the issue it had been close to resolution but talks stalled "two days ago."

Israeli and Palestinian demonstrators gathered on Sunday outside the West Bank settlement of Maaleh Adumim in a show of solidarity with he prisoners. Israeli police said two of the Palestinians were arrested for blocking a public road.

The hunger strike has attracted widespread support throughout the Palestinian territories, and Mr Abbas said he had raised the issue in discussions with Israeli negotiator Yitzhak Molcho and US Secretary of State Hillary Clinton. Source: AFP (© Copyright of Telegraph Media Group Limited 2012. 05/14/12)