Palestinian officials said Saturday they expected a breakthrough soon on efforts to end a mass hunger strike by Palestinian prisoners in Israel, some of them close to death.
But Amin Shoman, head of a monitoring group of Palestinian political factions, said that if Israel gave a negative response, prisoners would intensify their fast and break off further talks with prison authorities.
"The prisoners will stop taking vitamins and water and stop negotiations with the Israel Prisons Service if they get a negative answer," he told AFP.
Shoman and an official of the Palestinian Prisoners' Club, which tracks the well-being of Palestinians in Israeli jails, said they expected Israel to announce "within hours" its decision on demands by what Israel says are currently 1,550 hunger strikers.
They are protesting against solitary confinement, detention without charge and restrictions on family visits, education and various privileges.
He said the Israeli Prisons Service was expected to facilitate visits to prisoners by relatives from Gaza, who are not normally allowed to leave the coastal strip and travel through Israeli-held territory, to resume prisoner studies and to make concessions on solitary confinement.
Shoman added that two prisoners were moved from isolation cells on Friday, leaving 17 whose transfer is still a main Palestinian demand.
Prisons service spokeswoman Sivan Weizman said it had been decided to move two prisoners from solitary confinement but could not say on Saturday if the decision had been implemented yet.
Gaza's Hamas prime minister said intervention by Egypt had brought the issue closer to a solution.
"There was progress in talks between Egypt and Israel," Ismail Haniya said in a statement. "This is an important development concerning the demands of the prisoners."
Egypt helped broker a deal in which Israeli soldier Gilad Shalit was freed in October after more than five years of being held by Gaza militants in exchange for the release of 1,027 Palestinian prisoners from Israeli prisons. Haniya has asked for its intervention in the current hunger strike.
In a statement, former British prime minister Tony Blair, special envoy for the Middle East peace quartet -- the EU, United States, Russia and United Nations -- said he was "increasingly concerned about the deteriorating health conditions" of the hunger strikers.
He said that he had over the last week "engaged Israeli officials at all levels urging them to take all necessary measures to prevent a tragic outcome that could have serious implications for stability and security conditions on the ground."
Resolving the crisis in the next few days is key ahead of Nakba Day, on May 15, which commemorates the exodus of hundreds of thousands of Palestinians following the creation of the Israeli state in 1948.
The anniversary is normally marked by protest and heightened tensions in the Palestinian territories.
On Friday, the World Health Organisation urged Israel to give quick and suitable health care to Palestinian hunger strikers, including their transfer to civilian hospitals.
The UN agency said it was "extremely concerned" about their health, noting one suffered from the genetic blood disorder thalassaemia and has "refused his regular life-saving blood transfusions in addition to food."
"WHO calls on the Israeli authorities to ensure immediate and adequate access to appropriate ongoing health care for the hunger-strikers," it said in a statement from its Jerusalem office.
"WHO also requests Israel to ensure that ... release to hospital be facilitated for prisoners requiring medical treatment."
The hunger strikes have drawn international attention, with the European Union and United Nations expressing concern.
Two of those protesting, Bilal Diab and Thaer Halahla, marked their 74th day without food on Saturday.
The hunger strikes have widespread support among Palestinians who have staged regular demonstrations in solidarity with the prisoners.
Later Saturday, a joint Arab-Jewish rally took place in Tel Aviv's mixed Jaffa neighbourhood.