ABC News' George Stephanopoulos reports: If Republican presidential candidate Sen. John McCain doesn't vote for the Bush administration's $700 billion economic bailout plan, some Republican and Democratic congressional leaders tell ABC News the plan won't pass.
"If McCain doesn't come out for this, it's over," a Top House Republican tells ABC News.
A Democratic leadership source says that White House Chief of Staff Josh Bolten has been told thatDemocratic votes will not be there if McCain votes no -- that there is no deal if McCain doesn't go along.
McCain, taking questions from the traveling media today for the first time in 40 days, said he doesn't yet know how he will vote on the bailout.
But when he was asked by ABC News' Ron Claiborne what he would do if the fate of the bill was in his hands, he said Senate Democrats should not use his vote as the determining factor on the success of the bill.
"This issue should be - and their vote should be determined in how we can resolve this crisis and get America going again," McCain said. "This is a huge crisis. We know, in the words of many experts and mine, this is the greatest financial crisis since World War II. So to somehow, for the Democrats to say that their vote is going to be gauged on my vote frankly doesn't do them a great deal of credit.
"Their first and only priority should be making sure this economy recovers and get back on our feet again," McCain said.
McCain has expressed concerns about Treasury Secretary Henry Paulson and Federal Reserve Chairman Ben Bernanke's plan, which would amount to costing the American taxpayer two Iraq wars.
The Republican presidential candidate has suggested the original proposal lacks sufficient oversight, and he has said whatever plan emerges should protect family savings, homes, and student loans, and should eliminate obscene CEO compensation packages.
McCain said this week that any company that receives government aid should not be compensated more than $400,000 -- the highest-paid government employee.
McCain spokesman Tucker Bounds told ABC News' Jake Tapper that McCain has not made a decision one way or another.
"John McCain has been very clear that he has certain reservations about the details of the agreement that has been released at last notice," Bounds said. "There is no final agreement to review, but when there is John McCain will weigh in responsibly and appropriately."
Administration officials went to Capitol Hill Tuesday to urge Congress to pass the bailout package quickly, arguing the nation's economy is teetering on the brink of a major recession.
Some senior Democrats on Capitol Hill have voiced concern that McCain will continue to oppose the Bush administration's plan as a way to position himself as a critic of Wall Street and the Bush Administration.
If McCain doesn't vote for the legislation, other Republicans might follow suit, leaving the Democratic-led majority to fight in Congress to pass the risky bailout plan.
However a Democratic congressional leadership source tells ABC News' Jake Tapper that Paulson went so far as to assure Democratic leaders that McCain "won't be a problem" -- in other words that McCain will vote for the proposal.