Israeli Prime Minister Ariel Sharon may modify his plan to pull out of the Gaza Strip after it was strongly rejected by his own party, Mr Sharon's deputy said.
Critics say the poll was a tactical mistake for Sharon
Ehud Olmert said Mr Sharon made the remarks at a meeting with lawmakers from his governing Likud party.
"The prime minister said 'We have to put together a plan, perhaps not an identical one, in order to continue forward,'" Mr Olmert told reporters.
Final results show that 59.5% of the Likud party voted against the plan.
Mr Sharon - who says he will not resign despite the setback - subsequently survived a confidence vote brought by the opposition in the Israeli parliament, the Knesset.
He also warned Likud members that tough decisions lay ahead.
However, he refrained from declaring his Gaza plans dead.
Palestinian gunmen killed a pregnant Jewish settler and her four young daughters during Sunday's vote.
Some analysts said opposition to Mr Sharon's plan may have been boosted by the killings.
Mr Sharon's proposals call for Israeli troops and all 7,500 Jewish settlers to leave the Gaza Strip, with only a military presence left along the border with Egypt.
Following Sunday's vote, Mr Sharon said: "I receive the results of the vote with sorrow but I will respect them."
"The Israeli people did not elect me to sit on my hands for four years," he said.
Polls have shown that the country at large supports his proposals.
The prime minister said he would consult Likud and its coalition partners in the coming days.
The White House said on Sunday night that it stuck by its support for Mr Sharon's Gaza plan.
Israeli media are calling the result of the Likud vote one of the worst setbacks in Mr Sharon's long career.
Our correspondent says Mr Sharon may still present the withdrawal plan to his cabinet and to parliament, where it stands a good chance of being approved.
He adds that Mr Sharon may first have to reshuffle his government and may fire ministers he blames for the "no" vote. There is already speculation that the first to go might be the Finance Minister, Benjamin Netanyahu.
Mr Sharon may also decide to introduce new legislation to allow a national referendum on the Gaza plan, which is supported by a majority of Israelis, our correspondent says.
'Israel bigger than Likud'
Turnout in the Likud vote was reported to be as low as 35%.
Uzi Landau, the Likud cabinet minister leading the opposition campaign, said it was time to come up with an alternative to the "highly risky" disengagement plan.
"The largest part of Israel thinks that this plan was a mistake and we will have to take another one," he said.
However, Tommy Lapid, whose Shinui Party is part of the governing coalition, said Likud could not determine the fate of the nation and demanded the issue be discussed in cabinet.
Uri Dromi, a spokesman under the former Labour government, said he had backed Mr Sharon's plan and accused the prime minister of making a tactical mistake.
"He should have gone ahead with this and then brought it to the Knesset," he told the BBC's Newshour programme.
The Palestinian Authority, which believes Mr Sharon's plan to withdraw from Gaza will lead him to harden his position on the West Bank, responded to the Likud vote by saying that the party had no right to decide on Palestinians' fate.
Palestinian Prime Minister Ahmed Qurei said the poll result should act as an incentive to resume negotiations about Palestinian statehood.