A high-ranking official close to Israeli Prime Minister Ariel Sharon on Sunday equated support for the unofficial peace plan, due to be signed in Geneva on Monday, to abetting terror and undermining the internationally-backed "roadmap" plan.
"It should be clear that meeting with those who are going to dance around the golden calf in Geneva are making a mistake, because it is encouraging terrorists and harming the 'roadmap' which the international community and especially the United States have sponsored," he told AFP on condition of anonymity.
Israel had remained unmoved by Europe's open support for the initiative, seen by some commentators as an attempt by Brussels to retake the lead in the Israeli-Palestinian peace process.
Despite assurances of Washington's unwavering commitment to the "roadmap", Sharon's government has appeared more anxious over Washington's warming up to Geneva.
US Secretary of State Colin Powell sent a letter of encouragement to the blueprint's initiators and the Israeli official's unequivocal comments came amid reports that a Geneva delegation might be received in Washington.
According to Israeli public radio, Sharon is expected to warn the United States against such a move during his scheduled meeting Sunday with Washington's top envoy to the region, William Burns.
"One should bear in mind that in some democratic states such as the United States, those who are responsible for this initiative and thought it appropriate to sign an agreement with foreign agents without any official mandate, would be prosecuted," the Israeli official added.
Sharon dismissed the plan immediately after its release in October, and stepped up his anti-Geneva offensive Thursday.
"Geneva is an attempt to do something only a government can do. Only a government can conduct political negotiations and sign an agreement," Sharon told members of the Israeli press.
"It is damaging and embarrassing for Israel, it's a mistake to put on such a show and at the same time jeopardise a program which is the only one that can bring a solution," he added, in reference to the "roadmap".
Sharon's bureau chief Dov Weisglass reportedly tried during talks in Washington last week to convince the US administration that Geneva was a plot by the Israeli left-wing to undermine Sharon and make a come-back on the domestic political scene.
The two main figures behind the document, former Israeli minister Yossi Beilin and senior PLO official Yasser Abed Rabbo, told the Israeli media that their meeting with Powell was confirmed.
But Israeli newspapers reported that US congressmen supporting Sharon's government were trying to scupper the meeting.
In a rare financial sanction against its ally, the United States decided recently to deduct almost 300 million dollars from loan guarantees to protest against Israel's spending on its West Bank barrier and settlement development.
The Geneva plan deals with all key issues in the Israeli-Palestinian conflict and involves significant concessions from both sides.
Israel would have to relinquish most the West Bank and share sovereignty over Jerusalem, while the Palestinians would waive the right of return of 3.8 million refugees.
It was drawn up by Israeli left-wingers and leading Palestinian figures.