Sharon nailed the support of the centrist Shinui party late on Saturday in exchange for $160 million of additional allowances for discharged soldiers, students, cultural and scientific institutions and the environment.
If the budget were not adopted by the end of the month, the government would fall, forcing early elections and throwing the Gaza plan into jeopardy.
Shinui leader Yosef Lapid told public radio on Sunday that his party's 14 opposition MPs would back the budget to save the Gaza pullout despite failing to secure its demands for a civil marriage bill.
Matter of course
"We agreed to the budget because for us, disengagement, is essential," said Lapid. Parliamentary debate on the bill will begin on Monday.
Its crunch second and third readings on Wednesday are now largely a matter of course.
For right-wingers opposed to Sharon's Gaza pullout, the only remaining political weapon in their arsenal is an unpopular referendum bill, which faces a preliminary vote on Monday but has zero chance of success.
"The budget adventure has dissipated, Lapid surrendered and all that remains is to make sure that the referendum gets the kiss of death in the Knesset tomorrow for the job to be complete," ran an editorial in the Maariv daily.
"We agreed to the budget because for
In a seperate development, Defence Minister Shaul Mofaz has ordered Israeli occupation forces to delay the transfer of the West Bank town of Qalqiliya to Palestinian security control.
The minister said Palestinian police have not carried out their promise to disarm resistance organisation in two towns that already have been handed over, Israel Radio reported on Sunday
Mofaz warned last week that the handover - a key part of the truce Israel and the Palestinians declared last month - might not proceed because resistance organisations have not been disarmed.
Israel transferred the West Bank town of Tulkarim last week, and Jericho a week earlier.