Honolulu Mayor Mufi Hannemann took a significant fund-raising lead over his opponents by adding more than $640,000 to his campaign coffers in the first six months of this year.

Hannemann, who is facing nine opponents, including City Council member Ann H. Kobayashi and University of Hawai'i engineering professor Panos D. Prevedouros, has nearly $2.7 million in advance of the Sept. 20 primary election.

Between Jan. 1 and June 30, Hannemann raised $642,514.49, according to campaign fund-raising reports filed yesterday.

Kobayashi raised $5,485.24 during the same period and $34,650 in 2007. Prevedouros has yet to report any campaign contributions.

"I'm very grateful and very humbled by the support for my performance as mayor of Honolulu, as reflected in the contributions we've received to date," Hannemann said yesterday in a statement. "My pledge is for my team and I to continue working hard on behalf of the people of Honolulu to keep their trust and confidence in our endeavors."

Kobayashi and Prevedouros yesterday acknowledged Hannemann's sizeable cash advantage but said they were not intimidated.

Kobayashi, for example, said she is in the process of renting a campaign headquarters while volunteers are making signs and T-shirts.

"Money isn't everything. Money is power but so is people power, and I think people power is greater," said Kobayashi. "We'll have hot dogs rather than fancy food but that's OK. We're running a real grassroots campaign and it feels good to be out there listening to people and talking to them. The reaction has been heartwarming."

Prevedouros said he will not be advertising on television but will instead use the Web and tools such as e-mail and YouTube to get his message out. Each day, Prevedouros is filming YouTube spots at his Queen Street headquarters and coordinating them with e-mail and a planned radio campaign.

He said his campaign should be able to raise "low six figures" by September but that it will be enough to compete.

"We'll have enough money to get a quality message out. There is no way to compete with $2.5 million but one of the reasons the mayor is collecting is because of his high political ambitions. I'm sure he's shooting for the governorship or the U.S. Senate and he needs the money to compete at those levels," said Prevedouros.

Hannemann has said he is focused on winning re-election as mayor.

Neal Milner, a political scientist and ombudsman at the University of Hawai'i-Manoa, said Hannemann's large fundraising lead and high approval ratings, among other factors, give him a sizeable advantage heading into the primary election.

The fact that Hannemann has emerged with favorable ratings and considerable fund-raising even as the future of rail transit — a contentious municipal issue —remains undecided is an indication of his advantage, Milner said.

The latest Hawai'i Poll showed Hannemann's approval rating at 80 percent. Only 13 percent of those polled said they disapprove of Hannemann's overall performance.

"It's (the fundraising's) a huge advantage but it's about more than just money now," said Milner. "The Hawai'i Poll shows he has very high approval rating and, secondly, it's really not all that easy for a candidate to mobilize around the anti-rail effort. You have candidates who run for reasons other than wanting to win. That's not the case for Panos and not the case for Ann Kobayashi, and they're the ones who really have the high mountain climb."

The city's controversial plan to build a $3.7 billion elevated commuter rail system, the increased tax to pay for the rail, the overflowing city landfill, rising sewer fees, aging infrastructure and the growing homeless population have proved contentious issues but have done little to impede Hannemann's fundraising efforts.

A.J. Halagao, Hannemann's campaign coordinator, said the next fundraising cycle also got off to a good start as 4,000 people attended a stew-and-rice gathering at Blaisdell Center last week.

"Altogether, these events reflect strong and broad-based grassroots support for the work the mayor and his administration are doing at city hall," said Halagao. "With this level of support and the efforts of our campaign volunteers, our goal is to return the mayor and his team to Honolulu Hale for a second term."