Opponents of Metro’s $3.5 billion bond referendum have formed a political action committee to lead a grass-roots campaign to curtail what they say is wasteful spending by the regional transit agency.

“To ask for $3.5 billion is irresponsible,” said Bill Frazer, one of the organizers of the Responsible Houston PAC and a former Houston city controller candidate.

The Metropolitan Transit Authority is asking for voter approval to borrow $3.5 billion, to paid back by future revenues from its 1 percent sales tax, to start work on its proposed $7.5 billion regional plan. Metro hopes to receive federal funding to cover about $3.5 billion to build many of the projects. The remaining $500 million would come from existing agency funds in future years.

Transit officials want the money to add 75 miles of rapid bus service, 16 miles of light rail and nearly $600 million in local bus system enhancements, including additional service along key routes and new or restored sidewalks and bike lanes to and from bus stops.

Supporters have said it is down payment on needed transit projects the region has waited on for too long. Critics, however, cite Metro’s stumbles in the past as proof giving transit officials a “blank check” is risky.

“Metro cannot be trusted,” said Jim Scarborough, who led opposition to the bus rapid transit lanes under construction along Post Oak Boulevard.

TRANSIT BOND: Metro supporters have nine weeks to sell bond plan to voters

Opponents used the Post Oak project as the backdrop for their announcement Tuesday, noting that Metro is asking for money to build 75 miles of bus rapid transit in the region despite having nothing to show Houstonians are eager to hop aboard. Critics also noted Metro’s newest light rail lines have never delivered the ridership officials promised when they started construction and failed to build many of the things promised voters in 2003 — as they used the $640 million voters approved to build three rail lines and did not add the park and ride locations and increased bus service promised by the ballot item.

“Before we do another blank check, someone needs to hold someone accountable for the past,” said Wayne Dolcefino, a media consultant that helped organize Tuesday’s announcement.

With so many areas in need of improved street drainage, Frazer said transit officials should invest their money there — something he said is possible because Metro’s agreement with cities promises 25 percent of the transit sales tax for street and drainage projects. Nothing, Frazer said, prohibits Metro from spending more than a quarter of the money for streets.

Frazer said Responsible Houston was just beginning its fundraising and planned a social media campaign to oppose the Nov. 5 election. Metro, meanwhile, plans to spend $8.5 million to explain the plan to residents via mailings and advertisements, while a PAC formed to support the plan has raised at least $250,000.

dug.begley@chron.com