Republican challenger Ed Gillespie, in the studios of WCVE in Richmond, listens to a question in the final minutes of his debate with Sen. Mark R. Warner this week. (Timothy C. Wright/For the Washington Post)

Republican Ed Gillespie pulled television ads planned for most of the week in his race against Sen. Mark R. Warner (D), and his campaign acknowledged that he does not have the financial resources to match the popular Virginia incumbent.

Gillespie’s campaign will be back on the air Saturday with a $300,000 buy, spokesman Paul Logan said, but observers said the gap is an indication of a struggling campaign.

“It may be a financial necessity, but it’s certainly not a good sign for the campaign [to go off the air] so close to the election,” said Mark Rozell, acting dean of the School of Public Policy at George Mason University. “Unless he has some trick that will get him attention in some positive way, he has to be out there getting ads everywhere that he can.”

Logan said the campaign will have enough money for a strong finish,but he conceded that going dark on TV was a financial decision.

“We knew from the start that we weren’t going to outspend Senator Warner,” he said. “We had a strong fundraising support in the third quarter, and we’ll have the resources to execute our plan.”

Although the outlook for Democrats nationally is gloomy, and control of the Senate is at stake, Gillespie’s campaign against Warner has always been viewed as an uphill battle. Warner, a former governor, has maintained a popular brand as a pragmatic, deal-oriented centrist with strong ties to the state’s Republican-leaning business community. A first-time candidate, Gillespie, the former chairman of the Republican National Committee, started with far less name recognition after a long career in lobbying and party politics that Warner has exploited in campaign ads.

Those disadvantages for Gillespie have been reflected in the dollar figures.

Donors have tended to steer their money to more-promising Republican challengers in Colorado, Iowa and North Carolina — and to surprisingly tight contests in Kansas, Georgia and South Dakota. A super PAC backing Gillespie has raised only $150,000, and it spent a fraction of that sum. The National Republican Senatorial Committee’s independent expenditure arm has not been involved in Virginia.

Yet Gillespie supporters have been cheered by some recent developments. Last week, The Washington Post reported that Warner was among those high-powered Virginia Democrats who in early June pressed then-state Sen. Phillip P. Puckett (D-Russell) not to give up his seat in the middle of a bitterly partisan battle over health care. Warner has said that he “brainstormed” about a job for Puckett’s daughter but that he did not offer one.

Warner has been questioned repeatedly on the matter in interviews and during the candidates’ final debate this week.

Even before that issue surfaced, polls showed Warner’s lead narrowing from double to single digits in recent weeks. No public poll has been released since the Puckett story surfaced or since Monday’s debate.

Gillespie had a solid third fundraising quarter, taking in $1.8 million between July and September, compared with Warner’s $2 million in the same time period. In addition, the Republican lent his campaign $65,000, bringing his total receipts for the third quarter to $1.87 million. His campaign routinely takes note of the number of donors who gave money to Warner in the past and are now investing in Gillespie; the current total is 87.

Although observers suggest that Gillespie’s real focus might be on the 2017 election for governor, Logan said the only future campaign the candidate is thinking about is reelection to the Senate.

However, Warner enjoys a formidable advantage in cash on hand going into the final weeks of the campaign, which is likely to have a blitz of ads in the vote-rich, and very expensive, Northern Virginia media market.

The senator has $8 million to spend, compared with Gillespie’s $2 million, and he has benefited from more outside spending in support of his campaign. A super PAC has spent more than $2 million to back his campaign, according to campaign finance reports.

Warner has suggested twice publicly that the candidates bar super PACs from the race; Gillespie has scoffed at that proposal as disingenous given his rival’s edge in outside support.

Gillespie’s most recent ad, which debuted Oct. 3, contends that Warner has “lost his way” in the Senate, that he is a regular ally of President Obama’s and no longer resembles the popular governor he once was. This week, Warner released an ad in which former Republican senator John W. Warner endorses his candidacy, saying that “while we come from different parties, we both believe in putting Virginia first.”

Campaign finance reports released for other Northern Virginia races showed:

In the 10th Congressional District, Republican state Del. Barbara J. Comstock raised $1,241,793, compared with Democratic Fairfax County Supervisor John W. Foust’s $858,833, in the race to succeed retiring Rep. Frank R. Wolf (R). Foust also lent his campaign $150,000 in the most competitive House race in the state this year.

In the 8th District — where a reliably Democratic seat is being vacated by Rep. James P.Moran Jr. — Democrat Don Beyer outraised Republican Micah Edmond, $569,127 to $37,177.