The Honolulu Authority for Rapid Transportation will hold off on putting out bids for the final leg of rail construction through the city center until a 0.5 percent surcharge on Oahu’s general excise tax is approved to pay for a growing shortfall on the project.

On Thursday, HART Executive Director and CEO Dan Grabauskas said the agency planned to wait until the Honolulu City Council approved the tax extension — something it has been debating for months — before asking contractors to submit prices for construction.

He added that HART planned to put the city center segments out to bid this week, and noted that every day that goes by will lead to a delay in opening up the 20-mile rail line to passengers, which is currently scheduled to occur in 2021.

“We have said before that if we don’t put the contract out on the current schedule it is a day-for-day delay,” Grabauskas told the HART Board of Directors on Wednesday. “And delay does cost money.”

The board went along with Grabauskas’ suggestion to wait for a council decision. HART Board Chairman Don Horner admitted that mistakes have been made, and that the council is well within its right to scrutinize the project before approving the extension.

Honolulu’s rail project is now expected to cost $6.6 billion. Once construction is completed it will run from East Kapolei to Ala Moana Center and include 21 rail stations.