DENVER -- Gov. Bill Ritter vetoed a bill Thursday that would have allowed firefighters to unionize, drawing criticism from the AFL-CIO, who questioned the union's support for the Colorado democratic governor.

Senate Bill 180 would have given firefighters the right to unionize without getting local government approval.

Ritter, who has angered unions with three other vetoes since he took office, said the decision of whether to allow firefighters to unionize should be left to local governments. He said he still supports unions and firefighters, but he chose to support bills this year that help all workers who are struggling with the faltering economy, not just union members.

"As the son of a union member, and a former union member myself in earlier years, I have long believed that collective bargaining can create a positive working relationship for public sector employees and local governments," Ritter said in an afternoon speech announcing the veto.

"Changing our current system of local voter approval of collective bargaining and overriding the will of the voters who have rejected collective bargaining is not the appropriate solution," Ritter said.

Local firefighters in Denver, Aurora, Thornton, Pueblo, Greeley, Longmont and Englewood can already obtain collective bargaining rights through voter approval in their local communities. Other communities have opted against it, and the bill would have gone against the will of the voters in those areas, Ritter said.

Unions reacted swiftly.

"This veto is an outright rejection of the most basic, core value of our movement -- the right of all workers to have a voice on the job through collective bargaining,” stated Dwayne Stephens, president of the Colorado AFL-CIO.

Stephens said the bill was necessary so firefighters and local governments could work on safety issues.

Ritter said the claims by firefighters that they need collective bargaining to address equipment purchases and safety issues will be reviewed by the Department of Public Safety and if legislation is needed, they can do it next year.

Ritter got support from the chair of the Metro Mayors Caucus and Mountain View Fire District Deputy Chief Steve Pischke, who asked Ritter to veto the bill because they believe it would interfere with their ability to negotiate their own agreements with their firefighters.

“The state should not be telling local voters or local elected representatives what to do when it comes to personnel matters like this,” Littleton Mayor Doug Clark said.

“Ritter should have brought the right people together to make an honest attempt to work through his concerns on this bill. There was never a willingness on his part to engage in any meaningful discussion. This basic lack of effort makes the veto very hard to swallow,” said Colorado AFL-CIO Executive Director Mike Cerbo.

Senate Bill 180 is the fourth major labor bill Ritter has vetoed. It may also be one in which the governor may lose support from unions.

“We’re going to have to take a hard look at where we stand with Governor Ritter. Our hope has always been to forge a better working relationship with him, but we’ll have to discuss with our affiliates how the vetoes impact how we move forward,” Cerbo said.

"When he campaigned, he made it clear he was behind the labor movement. We're tired of seeing bill after bill falling to his pen. He's not the man we thought we were electing," said Steve Vairma, secretary treasurer of Teamsters Local 455.

"Gov. Ritter continues to disappoint working families, undercut our economic recovery in Colorado, and buy into the business versus labor corporate mentality that President Obama says is outdated and counterproductive," said Crisanta Duran, legal counsel for the United Food and Commercial Workers Union.

The UFCW is seeking a new contract with Colorado grocery chains. It supported a bill (House Bill 1170) that would have provided unemployment benefits to workers locked out by employers during a labor dispute. Ritter vetoed that bill last month.

The veto capped a whirlwind day of bill signings, with bill sponsors and supporters being shuttled in and out of the governor's office. The governor signed so many bills, he ran out of pens.

The other major bill signed on the final day of ceremonies was a new law establishing regional tourism zones to allow local governments to set up regional tourism projects (Senate Bill 173). Several groups have expressed interest in building auto race tracks if the state paved the way.

Other new laws include the Innovative Auto Act, extending tax credits to those who convert their vehicles to run on cleaner-burning compressed natural gas, and a law allowing drivers to operate low-speed electric vehicles on more roads. Another law reopens the Colorado Office of Film, Television and Media and provides tax incentives to attract and grow film production throughout the state.