WASHINGTON – Senate leaders vowed Thursday night to revive stalled immigration legislation as soon as next week, capping a furious rescue attempt led by President Bush.

The decision, announced by Majority Leader Harry Reid of Nevada and his Republican counterpart, Sen. Mitch McConnell of Kentucky, envisions a final vote on the complex bill before lawmakers begin their Fourth of July vacation.

The legislation has generated intense controversy, particularly for provisions that could lead to eventual citizenship for many of the estimated 12 million immigrants now in the country unlawfully. The bill also calls for greater border security and a crackdown on the hiring of illegal employees.

Critics of the measure succeeded in sidetracking it last week, and given their continued opposition, the decision to bring it back for more debate does not necessarily portend passage.

Reid and McConnell announced their plans in a brief, two sentence statement that capped days of private negotiations by key senators as well as Bush’s personal involvement.

“We met this evening with several of the senators involved in the immigration bill negotiations,” they said. Based on that discussion, the immigration bill will return to the Senate floor after completion of an unrelated energy measure now undergoing debate.

At the White House, spokesman Scott Stanzel said, “We are encouraged by the announcement from Senate leaders that comprehensive immigration reform will be brought back up for consideration.”

Two days ago, Bush made a rare visit to the Capitol for a meeting with Republican senators, where he urged them to give the bill a second chance. Earlier on Thursday, responding to a request from pivotal GOP senators, he threw his support behind a plan for $4.4 billion in immediate funding for “securing our borders and enforcing our laws at the work site.”

Precise details of the rescue plan were not immediately disclosed.

In general, according to officials familiar with the discussions, Republicans and Democrats will each have 10-12 opportunities to amend the measure, with the hope that they would then combine to provide the 60 votes needed to overcome a filibuster by die-hard opponents.

Officials said the Bush-backed plan for accelerated funding would be among the changes to be voted on. So, too, a proposal by Sen. Kay Bailey Hutchison, R-Texas, to toughen a requirement for illegal immigrants to return to their home country before gaining legal status.

But in a gauge of the complexity of the rescue effort, officials said the Senate’s decision last week to terminate a temporary worker program after five years would likely not be subject to change before a vote on final passage. Many of the bill’s strongest supporters opposed the five-year provision when it came to a vote last week.

Also to be protected from immediate change is a requirement to give enforcement agencies access to information that immigrants provide on their applications for legal status.

The officials spoke on condition of anonymity, saying the negotiations had been conducted in private.

“We’re going to show the American people that the promises in this bill will be kept,” Bush said, two days after launching a personal rescue mission.

Any agreement was ultimately subject to approval by Reid, who has said repeatedly it was up to Bush and Republicans to line up the votes needed to advance the measure if it was to be brought back to the Senate for debate. Reid, who has expressed misgivings about elements of the bill, sidetracked it last week after supporters gained only 45 of the 60 votes needed.

Republicans accounted for only seven of the 45 votes, and Reid said earlier this week, “We’ll move on to immigration when they have their own act together.”

Bush’s decision to personally announce support for the accelerated funding reflected concerns expressed by Republican senators at a closed-door meeting on Tuesday. Several told him their constituents doubted the government was capable of following through on a commitment to enforce immigration laws.

In a letter sent to Bush before the meeting, Georgia Republican Sens. Saxby Chambliss and Johnny Isakson wrote, “This lack of trust is rooted in the mistakes made in 1986, and the continued chaos surrounding our immigration laws. Understandably, the lack of credibility the federal government has on this issue gives merit to the skepticism of many about future immigration reform.”

Under the legislation as drafted, money for border enforcement would be collected gradually as illegal immigrants pay the fines and fees needed to achieve legal status. The letter asked Bush to secure the border before other elements of the immigration measure go into effect, and the president agreed in his remarks to the Associated Builders and Contractors.

“One common concern is whether the government will provide the resources to meet the goals in the bill. They say, ‘It’s fine to talk about it, are you actually going to do something?'” he said.

“To answer these concerns I support an amendment that will provide $4.4 billion in immediate additional funding for securing our borders and enforcing our laws at the work site,” he said.

“By matching our benchmarks with these critical funds, we’re going to show the American people that the promises in this bill will be kept.”

Two Republican supporters of the legislation, Sens. Lindsey Graham of South Carolina and Jon Kyl of Arizona, had previously proposed advanced funding.

“The moment the presidential signing pen meets the paper these funds will be available,” Graham said in a statement welcoming Bush’s remarks.

But Sen. Jim DeMint, R-S.C., who opposes the legislation, took a different view. “I appreciate the effort to fund border security, but there’s simply no reason why we should be forced to tie amnesty to it.”