House lawmakers voted Tuesday to give RTD power to go directly to voters if the transit agency decides to ask for more sales taxes to fund the beleaguered FasTracks program.

It is more authority than RTD expected to seek later in the session. It was proposed by Rep. Andy Kerr, D-Lakewood, as an amendment to the transportation funding bill making its way through the legislature.

It also goes beyond the consensus of a task force of metro Denver mayors last week who were working with RTD on the FasTracks funding problem.

The amendment was tacked onto Senate Bill 108, dubbed FASTER, which among other things would raise vehicle registration fees to repair deficient bridges. It must return to the Senate because of the changes before it faces final passage.

RTD said it didn't request the amendment but worked with Kerr after he proposed it. Initially, it extended taxing authority to other transportation planning authorities, but that was taken out. Now it deals only with RTD.

RTD hasn't decided whether to seek a second FasTracks sales-tax hike but has estimated it would need between two- tenths and four-tenths of a cent. In 2004, voters approved a sales tax of four-tenths of a cent for FasTracks, equaling four pennies on every $10 of taxable purchases.

The mayors' group last week backed a more limited authority that would restrict RTD to a single ballot issue only for FasTracks, to include a sunset on any new tax and to get on the ballot only by citizen petition.

The House amendment contains no such restrictions. It permits the 15-member elected RTD board to put sales tax measures directly on the ballot. It also removed a proposed higher ceiling on RTD's sales tax authority of 1.5 cents per dollar, leaving no ceiling in place.

RTD's sales tax is maxed out at the current legal limit of a penny on the dollar. State law also requires RTD to get lawmakers' permission to put anything on the ballot. This amendment would remove that restriction. RTD says it should have the same ballot access as school boards, cities and other government entities.

Thornton Mayor Erik Hansen said the City Council there voted Tuesday evening to oppose the measure, though it backs the FASTER bill in general. Hansen said the mayors didn't agree to support broad-ranging authority for RTD to go to the voters.

"The amendment as written endangers the successful completion of FasTracks by alienating the support of the stakeholders needed to pass any ballot issue," Hansen said. "RTD and the Metro Mayors task force have been working hard to solve this problem, and now is not the time to play politics.

"If RTD wants our support, it has to work with us."

But RTD Chairman Lee Kemp said the agency takes the collaboration with the mayors seriously and hasn't predetermined the look of any potential ballot measure.

"The RTD board is continuing to work with the Metro Mayors task force to determine the best way to complete the FasTracks plan," Kemp said, "which may or may not include a ballot initiative for additional funding and what the ballot should specify as to amounts and other requirements. This amendment would still require public votes on funding."

RTD determined last summer that it couldn't complete the FasTracks program in 2017 as promised to voters four years ago because of unanticipated cost increases that raised the initial estimate of $4.7 billion to $7.9 billion.

At the same time, the worsening economy has pulled the bottom out of RTD's revenue projections. RTD is debating the best way to proceed. Its options include delaying completion of transit corridors as existing revenues allow them to be built more slowly, cutting parts of the program to whatever it can afford to build by 2017, and seeking more revenue such as a second sales tax hike to complete it by 2017.

Next week, RTD expects to have updated cost and revenue estimates, and it is expected that the $7.9 billion cost will come down because of the impacts of the recession on prices.

But the revenue projection may drop even more, leaving a gap in the program and the need to cut projects, extend the schedule or seek additional funding.

The Metro Mayors Caucus task force working with RTD is part of the outreach the transit agency is doing to get a community consensus on which way to go.