MYRTLE BEACH, S.C. — About a dozen senior campaign staffers for Mayor Giuliani are forgoing their January paychecks, a sign of possible money trouble for the Republican presidential candidate and last year’s national front-runner.

“We didn’t ask anybody to do it,” Mr. Giuliani told reporters today after a town hall meeting at a charter school in Coral Springs, Fla.

“Some people volunteered to do it because they wanted to stretch out the money,” he said. “We’ve got quite a bit of money and they wanted to make sure that we had even more money for the end of this situation in Florida, so we could have enough on the air or whatever.”

At the end of December, the campaign had $12.7 million cash on hand, $7 million of which could be used for the primary, Giuliani’s campaign manager and one of those who now is working for free, Mike DuHaime, said. He disputed the notion of a cash-strapped operation and said Mr. Giuliani continues to bring in money; several fundraisers are scheduled this week in Florida.

The former New York mayor has yet to win a contest and is counting on a victory in delegate-rich Florida on January 29 to prove his candidacy is viable heading into the multistate contests slated for February 5, where he believes he can prevail in states such as California and Illinois.

“We’ll win Florida,” Mr. Giuliani said. “It’s an unconventional strategy, but I’ve never followed conventional wisdom before — it’s always worked. We think that Florida is a perfect place for us to sort of play out our entire campaign. All the themes in our campaign fit Florida. It’s a big state. It’s a big test. It’s a test that’s a microcosm of the country in many ways.”

It’s also a costly strategy: Florida and states that follow have some of the most expensive media markets in the country. And with so many states voting in such a short time period, candidates can do little else but rely on paid media — and news coverage — to get out their messages.

Republican strategists estimate that it will cost roughly $35 million to run one week of heavy levels of ads in the two dozen states that hold contests on February 5.

“Florida is real important to us, so we’re going to put if not everything into Florida, almost everything,” Mr. Giuliani said.

Mr. Giuliani has struggled to grab his share of the spotlight from rivals Michael Huckabee, winner in Iowa, and Senator McCain, the victor in New Hampshire, as well as Mitt Romney. Recent polls show Mr. Giuliani, the undisputed leader in most 2007 national surveys, losing his top spot.

The moneysaving effort raises questions about whether Mr. Giuliani’s bank account is as flush as it should be for him to cobble together enough delegates to secure the party nod. One aide said money was getting tight.

Through September, Mr. Giuliani had raised $45 million and had $11.6 million available for the primary campaign. With $7 million in cash on had at the end of December, that means Mr. Giuliani had spent nearly $5 million more than he took in during the last three months of the year.

All Republican candidates have struggled to raise money for the 2008 presidential race, an indication that GOP donors aren’t as energized as Democrats. Nearly every GOP hopeful set sky-high fundraising goals, but failed to meet them.

Mr. Giuliani, for his part, spent $300,000 on radio ads in Iowa and more money on direct mail, only to come in sixth. In New Hampshire, he spent some $3 million on TV and radio ads, and flooded mailboxes with direct mail; he finished fourth. He has been spending millions over the past month to run TV ads in Florida, and had a high rate of spending throughout most of last year.

Over the past few days, Mr. Giuliani has moved his handful of paid staffers out of Michigan and South Carolina to Florida, which has emerged as his best shot to re-ignite his campaign.

He also launched two ads in Florida, one of which urged viewers to discount media pundits and their election analyses. The ad seemed as much aimed at voters as it was to fundraisers, who are crucial to the well-being of his campaign at this stage.

Mr. Giuliani’s two new ads in Florida cost about $650,000 in Florida markets. However, he is not airing them in Miami, the most expensive market in the state. The campaign said he is relying on earned media there.

Mr. Giuliani has spent nearly $1.4 million in Florida on ads since December 28, according to data tracked by another presidential campaign.

Other candidates also are refocusing their strategies to deploy resources more wisely so they have enough cash to compete into February.

Mr. Romney, the multimillionaire former Massachusetts governor who lost both Iowa and New Hampshire, ended his television advertising in South Carolina and Florida to concentrate on Michigan. That state’s primary is Tuesday.