The initiative is being formally unveiled on Monday in Geneva. It contains a detailed blueprint aimed at resolving some of the most contentious issues in the Palestinian-Israeli conflict.
Washington’s top envoy William Burns, meanwhile, met senior Israeli officials on Sunday.
He is in the region meeting leaders in an effort to kickstart the "road map".
In another development, Hamas said on Monday it would participate in talks with other Palestinian factions in Egypt. It accused Israel of blocking representatives from the occupied Palestinian territories from flying to the Egyptian capital for talks scheduled on Tuesday.
The delegation will be headed by Musa Abu Marzuk, deputy president of the Hamas politburo.
Egypt is hosting 12 Palestinian factions, including Hamas and Islamic Jihad which are spearheading the Intifada, to encourage them to halt resistance attacks on Israel.
The chief driving forces behind the Geneva plan are former Palestinian information minister Yasir Abd Rabbu and former Israeli justice minister Yossi Beilin.
Israeli Prime Minister Ariel Sharon’s government has sharply criticised the initiative for bypassing official channels, claiming it will harm the US-backed “road map” aimed at ending the Palestinian-Israeli conflict.
But the “road map” is floundering as Israel has defiantly vowed to continue constructing its apartheid wall slicing off some of the most fertile parts of the occupied West Bank and separating Palestinian farmers from their land.
Israel has warned the international community not to throw its support behind the initiative, which has no official backing. However, it has already drawn European support and encouragement from Washington.
Palestinian factions have also voiced their opposition to the plan since it renounces the automatic right of return to 3.8 million Palestinian refugees.
The plan calls for the creation of a Palestinian state on 97.5% of the West Bank and Gaza Strip with shared sovereignty over Jerusalem.
About 700 guests, including intellectuals from both sides and former US President Jimmy Carter who helped broker the 1979 peace treaty between Israel and Egypt, will be attending the Geneva launch.
Yossi Beilin (C) hopes agreement
will rally public opinion
Palestinian President Yasir Arafat’s national security adviser Jibril al-Rajub will lead the official Palestinian delegation to the signing ceremony. But several prominent Palestinian officials due to attend the launch cancelled their trips amid continuing in-fighting over the plan.
Also attending will be the foreign minister of Qatar, envoys from Oman and Bahrain and all Arab states that have no formal relations with Israel, said organisers. Envoys from Morocco and Egypt will also participate along with a Saudi businessman with links to the government.
A 200-strong delegation flew out of Israel to take part in the ceremony.
Right-wing protesters, including National Union party MP Uri Stern, gathered at Ben Gurion International Airport to denounce the Geneva plan supporters. They carried banners reading, "You are going to sell Israel".
Switzerland, which financed and helped out the secret talks over two years, will oversee the signing ceremony.