WASHINGTON (Reuters)- After months of tossing charges at each other, Republican John McCain and Democrat Barack Obama came face to face at the White House on Thursday in high-stakes talks over a Wall Street bailout plan and their first debate hanging in the balance.

McCain emerged hopeful that progress on a $700 billion rescue of the financial industry would allow him to attend a debate with Obama on Friday in Oxford, Mississippi.

Obama said he would be there whether McCain was or not.

He suggested McCain was injecting presidential politics into negotiations over the rescue plan, one of many Democrats to howl about the Arizona senator’s abrupt suspension of his campaign to return to Washington to insert himself into the debate.

“The concern that I have ... is that when you start injecting presidential politics into delicate negotiations, then you can actually create more problems rather than less,” Obama told a news conference.

McCain senior adviser Steve Schmidt shot back that it was the top Democrat in the Senate, Nevada Sen. Harry Reid, who had said McCain’s help was needed to help corral Republican support for the plan.

The presidential campaign played out across Washington, from Capitol Hill to the White House to the television cameras a day before the first presidential debate is scheduled to take place.

McCain said progress was being made and he expressed confidence that a deal would be reached. Aides said he was working the phones to gain the support of Republicans uneasy about the cost of the $700 billion bailout.

“I’m very hopeful that we’ll have enough of an agreement tomorrow that I can get to Oxford ... I understand how important this debate is and I’m very hopeful but I also have to put the country first,” McCain told CBS News.

AIR OF CAUTION

But the McCain campaign was maintaining an air of caution as the candidate settled in for the night in the Washington area instead of flying to Mississippi as scheduled.

Obama made clear he would show up at the site of the debate at the University of Mississippi on Friday night and stage an event alone if necessary, putting pressure on McCain to attend the first of three face-to-face debates that may prove pivotal in the November 4 election.

“It is my intention to be in Mississippi,” Obama told ABC News. “I think he (John McCain) knows that I’m going to be there. So, you know, I hope that he is as well.”

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McCain and Obama stepped off the campaign trail to take part in the White House talks after McCain took the unusual step of suspending his campaign to work on the bailout deal and warned he would not attend the debate without an agreement.

Democrats accused McCain of pulling a political stunt in a scramble to regain his footing on the U.S. economy a week after saying economic fundamentals were strong despite the brewing Wall Street meltdown.

At the White House, a participant in the meeting, Republican Alabama Sen. Richard Shelby, said McCain and Obama “were very courteous to each other and very respectful.”

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Afterward, each candidate quickly ran to the television cameras and charges flew from both sides.

Schmidt accused the Obama camp of trying to buy television advertising space that McCain officials had given up during their campaign suspension, saying Obama acted in a “politically predatory fashion.”

Obama spokesman Bill Burton expressed doubts about McCain’s self-declared campaign suspension.

“Though the McCain campaign announced yesterday that they were also ‘suspending’ their attack ads, they continued to run Thursday,” he said.

Reid, a Nevada Democrat, said he believed Democrats and Republicans were moving toward a deal and that McCain would only get in the way.

“If we lose progress it is only because of one person -- that is John McCain standing in the way,” he said.