The four major candidates for Honolulu mayor exchanged barbs and tried to distinguish themselves from the pack at a final debate before Saturday’s special election.

But no new ground was broken during an otherwise boisterous and spirited forum broadcast live from the Blaisdell Center on KFVE, KGMB and KHNL.

Peter Carlisle, former prosecutor, defended himself from attacks by acting Mayor Kirk Caldwell that he accepted raises over the last few years while City Councilman Rod Tam attempted to fend off ethics questions about his use of campaign funds and controversial proposals he’s made as Council member and state legislator.

Caldwell continued to try to paint himself as different from former Mayor Mufi Hannemann. Caldwell, 57, has been acting mayor since late July. He was Hannemann’s managing director for two years before that and was a state representative before that.

Meanwhile, University of Hawaii civil engineer Panos Prevedouros steered much of the discussion back to his staunch opposition to the city’s $5.6 billion rail transit project and his promise to end the project through executive power.

Carlisle questioned whether Prevedouros was legally able to stop rail given that excise tax dollars, as well as federal funding, are designated for it. He also questioned whether it was the right thing to do since a majority of voters chose in 2008 to continue with the project.

Prevedouros said he could stop the project because as mayor he would have the executive power to simply not carry out the project. He said that a long-planned bike lane plan has been largely ignored by several mayors despite wide public support.

Carlisle said Prevedouros could have challenged and sought a re-vote on the public’s support for rail and did not do so.

Caldwell said the rail project’s budget and timetable are both realistic despite the skepticism of Prevedouros and other critics. There will be $3.5 billion coming from excise tax revenues while Congress is expected to provide the remaining $1.5 billion, he said. "The stars are aligned … we’re going to finish it by 2019."

Carlisle vowed that he would support rail only using the current funding mechanisms: using excise tax dollars and federal help but not other city funding.

Tam was asked, after supporting rail in recent years, why he suddenly was expressing ambiguity to the project during this summer’s campaign. "My proposal is that we carry on with rail provided at the time we have the means to support it," he said last night.

Carlisle, also 57, was city prosecutor of Honolulu for 16 years before resigning in July for run for mayor.

Prevedouros, 48, is a professor of engineering at the University of Hawaii at Manoa. He finished third in the 2008 mayoral election.

Tam, 56, is finishing his second four-year term as councilman representing the 6th District. He is barred from running for a third, consecutive term. Tam has been a senator and state representative.

In an independent poll in late August conducted on behalf of the Star-Advertiser and Hawaii News Now, Carlisle held a commanding lead with the support of 49 percent of respondents. Caldwell finished with 25 percent, Prevedouros received 11 percent and Tam got 4 percent.

Last night’s debate was the last chance for the major candidates to engage each other, and for the public to see them side by side, before Saturday’s election.