Mr Ariel Sharon's deputy said the Israeli prime minister would push through his Gaza pullout plan virtually unchanged.
Vice Premier Ehud Olmert predicted in a newspaper interview that Mr Sharon would win cabinet approval within weeks despite his party's rejection of the plan.
His comments came even as work was set to begin today on a new fence deep in the territory to secure a settler road. Mr Olmert said the barrier was a temporary measure until Israel withdrew from the Gaza Strip.
"We will implement the 'disengagement plan'," Mr Olmert told the Jerusalem Post. "The prime minister must now create a mechanism that will allow him to pass this resolution, and that he will do."
Mr Olmert dismissed media reports that Mr Sharon would slim down the pullout plan, limiting it to a handful of isolated settlements in Gaza. He said a scaled-back pullout was impractical and would not meet with approval from Washington, Israel's closest ally.
Mr Sharon's original plan envisaged scrapping all 21 Gaza enclaves, with 7,500 Jews amidst 1.2 million Palestinians, and four of 120 in the West Bank. He has made clear he wants to retain several larger West Bank settlement blocs.
The initiative has angered Palestinians who hope to set up a state on all the West Bank and Gaza Strip, lands captured by Israel in the 1967 Middle East war.
Military officials said a seven-kilometre (four-mile) fence would be erected on a settlers-only road leading to Gaza's Gush Katif Jewish settlement bloc after a woman settler and her four daughters were killed in an ambush there by Palestinian militants on Sunday.
Israel has drawn international condemnation for construction of a barrier that slices into the West Bank and is expected to extend more than 370 miles.