Benjamin Netanyahu has appealed to Palestinian President Mahmoud Abbas to call off the reconciliation agreement between Fatah and terrorist organisation Hamas.
The deal is to be celebrated at a Cairo ceremony tomorrow, paving away for a unity government and elections.
Although the terms have already been agreed, the Israeli Prime Minister, reiterating the concern of many Israeli and US officials, implored Mr Abbas "to choose the way of peace".
After a meeting with Quartet envoy Tony Blair, Mr Netanyahu said: "The agreement between Abu Mazen and Hamas deals a tough blow to the peace process.
"How can peace be reached with a government in which half of it calls to destroy Israel and even praises mass-murderer Osama bin Laden?".
His comments followed demonstrations in the Gaza Strip condemning the US for killing Osama bin Laden. Hamas Prime Minister Ismail Haniya described the al-Qaida leader as a Muslim warrior.