After hours of heated debate, the state House on Thursday moved the rail bailout bill toward a final vote.
House lawmakers approved the measure with no changes by voice vote, and the full chamber is expected to pass the bill on Friday. It will then head to the governor's desk.
The measure would generate nearly $2.4 billion to save the beleaguered project.
The vote came a day after the state Senate approved the bill in a 16-to-9 vote.
The timing of the special session deliberations remain of critical importance to the project.
The partially built rail line is years behind schedule and way over budget -- with the estimated price tag ballooning from $5.26 billion in 2014 to nearly $10 billion, including financing costs.
The city has only until Sept. 15 to show the Federal Transit Administration a plan to raise the money to cover the project's budget shortfall – or risk losing $1.55 billion in federal grant funding it has already received.
Lawmakers have called the funding bill a breakthrough compromise to bail out the project, but city leaders continue to insist the proposed deal leaves the project at least $600 million short.
The mayor has said he wants to support the deal, but is seeking some tweaks. The legislature's agreement extends the existing half-percent general excise tax surcharge on Oahu for three additional years through 2030, which will generate about a billion dollars.
Caldwell recommended that number be extended to five years. If lawmakers don't agree, Caldwell instead asked them for a promise.
The bill also raises the statewide hotel room tax 1 percent for the next 13 years -- which equates to about $1.3 billion for upfront construction costs. To help please the neighbor islands, the counties' share of the hotel tax goes up from $93 to $103 million.
The proposal would also reduce the state's administrative fee, or skim, on collecting Oahu's rail tax from 10 percent (around $30 million) to just 1 percent (about $3 million).
The bill would also require a state audit and annual reviews of the Honolulu Authority for Rapid Transportation. Additionally, the Senate president and House speaker will have the power to appoint two non-voting members to HART's board of directors.
Finally, the measure creates a mass transit special fund, where all the collected rail taxes will go and which the state would then distribute to HART to cover construction costs.