Republican presidential nominee Sen. John McCain, R-Ariz., and Democratic presidential nominee Sen. Barack Obama, D-Ill., right, participate in the first U.S. Presidential Debate at the University of Mississippi in Oxford, Miss., Friday, Sept. 26, 2008. (AP Photo by Jim Bourg, Pool)

OXFORD, Miss. -- Barack Obama accused presidential rival John McCain of supporting Bush administration policies that produced the current economic crisis Friday night in their first debate of the campaign for the White House. Both men readily agreed Congress must act soon to prevent millions of Americans from losing their jobs and homes.

Asked directly whether he intends to vote for a rescue plan taking shape in Congress, McCain said, "I hope so. ... sure."

"We haven't seen the language yet," Obama said. "I do think there is constructive work being done."

The two men stood behind identical wooden lecterns on the stage of a performing arts center at the University of Mississippi. It was the first of three presidential debates in a campaign in a close race with less than six weeks yet to run. The two vice presidential candidates will debate once, next week.

Obama wasted little time in going on the offensive, using the first question of the night to launch his first attack. Speaking of the crisis that has gripped Wall Street, he said, "We also have to recognize that this is a final verdict on eight years of failed economic policies promoted by President Bush and supported by Sen. McCain."

"And we can't afford another four," he added several moments later.

McCain sought to turn the tables on his rival by pointing out Obama has requested millions of dollars in congressional earmarks that he called pork barrel spending, including some after he began running for president.

As he does frequently while campaigning, the Republican vowed to veto any lawmaker's pork barrel project that reaches his desk in the White House. "You will know their names and I will make them famous," he said.

"This is a classic example of walking the walk and talking the talk," he added, accusing Obama of becoming a recent convert to the cause of opposing wasteful government spending.

"Eliminating earmarks also is not a recipe for how we're going to " put the country back on track, Obama replied.

The two men clashed over taxes and energy legislation as well in the 90-minute session. Ground rules had called for a debate on foreign policy, but moderator Jim Lehrer of PBS said he would not restrict the topics.

Lehrer tried early and often to draw the two White House rivals into a back-and-forth, and they plunged ahead.

"Sen. Obama has the most liberal voting record in the United States Senate. It's hard to reach across the aisle when you're that far to the left," McCain said.

The debate unfolded at a particularly tumultuous point in the campaign, with Bush and Congress struggling to avert a full-blown financial disaster.

McCain announced he would suspend his campaign earlier this week to return to Washington and take part in meetings on the crisis. Initially, he said he would not debate unless lawmakers had reached an agreement.

He reversed course earlier in the day, deciding to attend the debate, then return to the capital later.

The stakes were high as the two rivals walked onstage. The polls gave Obama a modest lead and indicated he was viewed more favorably than his rival when it came to dealing with the economy. But the same surveys showed McCain favored by far on foreign policy.

Both men were veteran debaters after winning their respective presidential nominations. Obama debated former rival Hillary Clinton more than a dozen times, while McCain stood on stage with his Republican rivals in numerous states.

Both candidates have been rehearsing extensively, Obama prepping with advisers at a resort in Clearwater, Fla., and McCain putting in debate work at his home outside Washington.

The two presidential hopefuls are scheduled to debate twice more, at Belmont University in Nashville on Oct. 7 and at Hofstra University in Hempsted, N.Y., on Oct. 15. Vice presidential contenders Sarah Palin and Joe Biden are to square off in a single debate Oct. 2 at Washington University in St. Louis.