BANGOR, Maine — City voters may get to have a say after all in whether Bangor should embark on the biggest construction project in its history.

Petitioners have gathered enough signatures to force a citywide referendum on whether Bangor should proceed with plans for the estimated $65 million arena and convention center complex.

Bob Cimbollek, Ken Wicks and Steve Sleeper, the three principal collaborators on the petition drive, delivered about 2,600 signatures Friday to the city clerk’s office, about 15 percent more than the 2,236 needed.

The clerk has 20 days to certify the petition, after which a vote would be scheduled.

“I should be happy, but I’m disappointed,” Wicks said outside City Hall, referring to the recent actions of what he called an “out-of-control City Council.”

City councilors have tentatively moved forward with a proposed 5,800 fixed-seat arena (with a maximum seating capacity of 8,050 for certain events) and an adjacent convention center to replace the aging Bangor Auditorium and Civic Center. The project currently is in what’s known as the design development stage, but the City Council has not yet fully committed to building a new complex.

The petitioners insist they are not against building a new arena and convention center; they just want taxpayers to have a vote. Although the city has hosted dozens of public meetings and workshops over the last few years on the topic, there has been no citywide vote.

Cimbollek and others have said the project is simply too expensive and critics do not believe the city has enough funding sources to pay for construction. He would rather see the city rehabilitate the existing facilities for a lot less money.

He said the petition-gathering process confirmed his belief that others share his concerns.

“Some were grabbing the clipboard out of my hand,” Cimbollek said.

City Councilor Gerry Palmer, who was at City Hall on Friday as the petitioners delivered signatures, said he respected the public process but he hopes supporters work hard to educate the public on the project.

“There is a lot of misinformation that’s out there and there will probably be more,” he said.

In all likelihood, if the signatures are certified, a referendum vote would be held in June since there already is an election scheduled. The City Clerk’s Office also is in the process of certifying petitions from a group seeking to overturn a recent council decision to consolidate police and fire dispatch services with Penobscot County.

Palmer said it is the right of the people to petition when they feel strongly about something.

“I expect we’ll see more down the road,” he said. “We’re elected to listen to the people and we believe we’ve done that.”

After several years of discussion, councilors finally are united in their support for the arena project. Although some have balked at the high costs, even the most fiscally conservative councilors are comfortable that the costs will be covered without relying on taxpayers.

More recently, councilors worked with architect Don Dethlefs and construction manager Cianbro Corp. to alter the initial design plans to bring the overall cost down to about $65 million, in large part to assuage public concerns.

The city has designated its share of Hollywood Slots proceeds to pay for the arena and convention center. Additionally, councilors have committed to using a portion of Bangor’s downtown tax increment financing district funds. Finally, a friends group of local business and civic leaders has formed to solicit private sector donations once the project officially gets a green light.

Based on projections from the main funding source, Hollywood Slots, Bangor could afford a $54 million project using that source alone. The city so far has collected about $10 million from the racino and expects to collect between $2.5 million and $3 million annually over the next three decades.

Wicks disputes those projections and says the city should use actual numbers. According to financial information provided by the state Gambling Control Board, the amount of slots revenue that went to Bangor in 2010 was about $2.1 million. In 2009, it was just under $2 million.

One variable that could change the equation is whether Hollywood Slots is successful in adding table games such as blackjack and poker. Voters last November approved a resort casino in Oxford County that would combine slot machines and table games.