Honolulu Mayor Mufi Hannemann announced this afternoon that he will run in the Democratic primary for governor, telling a rally that he will focus on issues such as education, the economy and the environment.

"It's all about fulfilling the promise that Hawaii is capable of producing home-grown leaders," Hannemann said at a rally at Fern Elementary School in Kalihi, where he attended as a child.

Hannemann will not officially file until just before the deadline in July.

Hannemann will face former congressman Neil Abercrombie in the Democratic primary in September.

Lt. Gov. James "Duke" Aiona is the leading Republican candidate.

Abercrombie, who resigned from Congress in January to focus on his campaign, has scheduled a 5:30 p.m. press conference. But he released this statement before the press conference and following Hannemann's announcement:

"Mayor Mufi Hannemann has been raising money and holding campaign rallies for the governor's race since June of last year, all the while using the city government and Honolulu's rail project in particular as political leverage. This latest pronouncement is just the latest step in planning to enter the race for governor sometime in July," Hannemann said.

"If he is truly running for governor, the Hawaii State Constitution requires the mayor to resign from office. Even if he has found a loophole to exploit, he displays a continuing willingness to violate the spirit of the Constitution for his own personal advantage. Although I was not required by law to resign, I did so because I didn't feel it was right to campaign for governor in this critical election year while holding public office and collecting a government paycheck. Mayor Hannemann has a different view."

The mayor's candidacy had long been expected and Hannemann supporters even opened up a headquarters on Kauai yesterday to add to a campaign committee, several union endorsements, a campaign Web site, and other steps that indicated the mayor would make a run.

In a release, Aiona said of Hannemann: "We can't afford him."

Aiona criticized the mayor for "a record of raising taxes and increasing the cost of living for our residents on Oahu."

Aiona added: "I'm running for governor to ensure balance, integrity and accountability in state government while reducing the financial burden on our working families and small businesses, creating jobs and investing in the quality of our education system so all of Hawaii's children have a brighter future."