After months of record-breaking fund-raising, a new sense of urgency in Senator Barack Obama’s fund-raising team is palpable as the full weight of the campaign’s decision to bypass public financing for the general election is suddenly upon it.

Pushing a fund-raiser later this month, a finance staff member sent a sharply worded note last week to Illinois members of its national finance committee, calling their recent efforts “extremely anemic.”

At a convention-week meeting in Denver of the campaign’s top fund-raisers, buttons with the image of a money tree were distributed to those who had already contributed the maximum $2,300 to the general election, a subtle reminder to those who had failed to ante up.

The signs of concern have become evident in recent weeks as early fund-raising totals have suggested that Mr. Obama’s decision to bypass public financing may not necessarily afford him the commanding financing advantage over Senator John McCain that many had originally predicted.

Presidential candidates in a general election have typically relied on two main sources of money: public financing, along with additional money their parties raise. In choosing to accept the public money, the McCain campaign now gets an $84 million cash infusion from the United States Treasury. Mr. McCain is barred from raising any more money for his own campaign coffers but can lean on money raised by the Republican National Committee, which has continued to exceed expectations.

Meanwhile, Obama campaign officials had calculated that with its vaunted fund-raising machine, driven by both small contributors over the Internet and a powerful high-dollar donor network, it made more sense to forgo public financing so they could raise and spend unlimited sums.

But the campaign is struggling to meet ambitious fund-raising goals it set for the campaign and the party. It collected in June and July far less from Senator Hillary Rodham Clinton’s donors than originally projected. Moreover, Mr. McCain, unlike Mr. Obama, will have the luxury of concentrating almost entirely on campaigning instead of raising money, as Mr. Obama must do.

The Obama campaign does not have to report its August fund-raising totals until next week, so it is difficult to tally what it has in the bank at this point. A spokesman said that August was its best fund-raising month yet and that the campaign’s fund-raising was on track. But the campaign finished July with slightly less cash on hand with the Democratic National Committee compared with Mr. McCain and the R.N.C. The Obama campaign has also been spending heavily, including several million more than the McCain campaign in advertising in August.

A California fund-raiser familiar with the party’s August performance estimated that it raised roughly $17 million last month, a drop-off from the previous month, and finished with just $13 million in the bank.

Still, the Obama campaign said last Thursday that it had raised $10 million over the Internet in the 24 hours after the speech by Mr. McCain’s running mate, Gov. Sarah Palin, at the Republican convention on Wednesday, a one-day record for the campaign.

David Plouffe, the Obama campaign manager, said the majority of the Obama campaign’s donors during the primary had yet to write checks for the general election. When they do, he said, it will be the equivalent of the large injection of cash the McCain campaign is receiving from the government — about $70 million or $80 million.

“We’re confident that we will meet our financial goals, but it’s hard work,” Mr. Plouffe said. “We have a long way to go in the next six weeks.”

Members of Mr. Obama’s national finance committee were briefed during the convention in Denver by Mr. Plouffe. Penny Pritzker, the Obama finance chairwoman, announced new state-by-state fund-raising goals. The decidedly business-oriented nature of the meeting reflected the burden on the Obama campaign in the coming weeks.

“I think McCain made the right call,” said Scott Reed, a Republican strategist who managed Bob Dole’s presidential campaign in 1996. “The Republican National Committee is strong. They have the resources to make this race almost financially on par.”

Democratic strategists disagree, pointing out that campaign finance rules impose serious restrictions on Mr. McCain’s ability to fully make use of his party’s bank account.

“It’s not just the limitation of dollars when you accept public financing, it’s the limitations that go with that spending,” said Tad Devine, a senior strategist for Senator John Kerry’s presidential campaign in 2004. Mr. Devine added that choosing to accept public financing was the Kerry campaign’s single biggest mistake because it limited the campaign’s resources.

The McCain campaign had by far its best fund-raising month ever in August, when it collected $47 million for its coffers and $22 million for the party, finishing the month with more than $100 million in the bank that will now be at the disposal of the R.N.C., according to several finance officials.

McCain fund-raisers said they also hope to raise an additional $100 million for the party in September and in October, taking advantage of the sizable contribution limits for the party. The party’s Internet fund-raising has also picked up significantly since the announcement that Ms. Palin would join the Republican ticket. Combined with the $84 million from public financing, that would leave the McCain campaign with about $300 million at its disposal.

A recent e-mail message to McCain fund-raisers unveiled new incentives to spur them in their final push. For the primary, anyone who raised $100,000 or more earned the title of Trailblazer, while those who raised $250,000 or more became Innovators. Now Trailblazers who raise another $100,000 for the party for the general election can become Super-Trailblazers, and Innovators who raise another $250,000 earn the title of Super-Innovators.

Officials have also sketched out plans for Ms. Palin to do some 35 fund-raisers over the next two months. Mr. McCain will be dispatched for only four major fund-raisers: one on Monday night in Chicago, in which the party raised about $4 million; another next week in Miami, then Los Angeles and New York in October, finance officials said.

But even if the McCain finance team, led by Lewis M. Eisenberg, a former Goldman Sachs executive, and Wayne L. Berman, a Washington lobbyist, meets its goals, the campaign will have complete control over only the $84 million from the federal government, as well as $19 million in party money that is permitted to be used in coordination with the campaign.

The Republican Party can spend unlimited amounts of its money independent of the McCain campaign. It can also split the costs of so-called hybrid advertisements with the campaign, commercials that must promote not only Mr. McCain but also other Republicans down the ticket, something media strategists said could be ineffective when trying to create a cohesive message. Nevertheless, McCain fund-raisers pointed out the pressure is now on the Obama campaign to raise far more than it ever has before.

The Obama campaign set a goal in mid-June of raising $300 million for the campaign and about $150 million for the Democratic Party over four-and-a-half months, fund-raisers said. As of the end of July, however, the Obama campaign was well short of the $100 million a month pace it had set, taking in about $77 million between the campaign and the party that month.

It is not yet clear whether the Obama campaign will be able to ratchet up its fund-raising enough in the final two months of the campaign to make up the difference.

Even Mr. Obama’s fund-raisers in Illinois were admonished in an e-mail message last Thursday to step up their efforts to “show the other regions that his home state still has it.” The donors, who were also reminded they had each promised to collect $300,000 for the campaign, were asked to raise $25,000 each for an event on Sept. 22 at a Chicago museum.

The new state-by-state goals unveiled by campaign officials in Denver stunned at least some in the room and included sizable increases for at least some states, according to interviews with several Obama fund-raisers.

The campaign has created a fund-raising committee, the Campaign for Change, which allows fund-raisers to harvest additional checks of more than $30,000 that will then be divvied up among state Democratic Parties in 18 battleground states, with Florida, Ohio, Pennsylvania and Michigan receiving the most.

In a campaign swing through South Florida over Labor Day weekend, Mr. Obama’s vice-presidential running mate, Senator Joseph R. Biden Jr., met with several small groups of major donors and sent out an e-mail appeal to supporters of his own unsuccessful presidential campaign, as well as to Jewish supporters. The effort brought in more than $1 million in four days.

Campaign officials expect their Internet fund-raising engine to ramp up as the election approaches. And they hope that much of the high-dollar fund-raising can be done without Mr. Obama. In the New York area alone, there are some 18 events planned in September, all with surrogates, including Mrs. Clinton, Caroline Kennedy and Gov. Bill Richardson of New Mexico.

But campaign officials conceded that Mr. Obama inevitably will have to make some appearances. On Friday night in New Jersey, Mr. Obama devoted five hours for two fund-raising events, including one at the home of the singer Jon Bon Jovi, in which the ticket was $30,800 a person. Mr. Obama is also scheduled to appear at back-to-back fund-raisers in Los Angeles on Sept. 16.