Rep. Marty WalshIt took less than 10 minutes: After ten mayoral hopefuls stepped off the stage and left a Dorchester union hall on Thursday night, the Greater Boston Labor Council quickly voted to throw its support to state Rep. Marty Walsh.

Walsh, who has represented Dorchester in the state Legislature since 1997, is a former laborer and top union official. Earlier this year, after announcing his run for mayor, he stepped down from the job of secretary-treasurer of the Boston Building Trades Council.

A few hundred delegates to the Greater Boston Labor Council, which represents 90,000 union members in the area, were in the room for the voice vote. The council includes utility workers, machinists, and the building trades, among others.

Rich Rogers, the GBLC’s executive secretary-treasurer, said the vote reflected a “consensus in the labor community.” “He stood with us for 17 years,” Rogers said of Walsh.

Last week, Walsh picked up the backing of the New England Regional Council of Carpenters. The Massachusetts Nurses Association endorsed him in May.

But several unions have not yet backed a candidate. For example, members of the Boston Teachers Union were inside the union hall and did not vote. Earlier on Thursday, BTU’s president, Richard Stutman, said the union will be endorsing a candidate in the final election, but may stay out of the September preliminary.

Other unions that have not yet endorsed include SEIU 1199, Boston Firefighters Local 718, and Local 26 UNITE HERE, which includes hotel workers, food services and gaming industry workers.

The mayoral candidates had to complete a GBLC questionnaire in order to be able to attend the forum. Rogers declined to release to the Reporter copies of the candidates’ answers. Only a blank copy of the 8-page questionnaire, which came with a separate one-page “Right to Organize Pledge,” was available to reporters.

The questionnaire included inquiries on whether candidates support Suffolk Downs’ bid to open a casino in East Boston and whether they would “use the moral authority of your office” to help private sector unions settle collective bargaining disputes. During the mayoral forum, panelists asked candidates questions based on their publicly unavailable answers.

Before the GBLC vote, 10 of the 12 candidates running for mayor made their case and pushed their labor ties to the crowd of union members and delegates at the IBEW Local 103 building on Freeport St.

For his part, Walsh said he was a second generation laborer – his father came over from Ireland and joined the building trades. The younger Walsh’s first job, according to his campaign, was the World Trade Center on Seaport Boulevard in South Boston. Public employee unions will be viewed as a “partner” in his administration, Walsh said.

Felix G. Arroyo, a city councillor at-large who worked as a political director for SEIU 615, noted his wife is a teacher. John Barros, a former member of the Boston School Committee, said his father had worked for the Plymouth Rubber Company, while Suffolk District Attorney Dan Conley pointed to his father working for the New England Telephone Company. “Your priorities are my priorities,” like workforce housing, job training, and good schools, Conley said.

John Connolly, a city councillor at-large who heads up the council’s Education Committee and has clashed with the teachers’ union, called the labor movement “crucial” to the middle class in Boston.

Charlotte Golar Richie, a former state representative from Dorchester, said she had a “near 90 percent” pro-labor voting record during her time in the House. Bill Walczak, co-founder of the Codman Square Health Center, said he met his wife during an iceberg lettuce boycott, based on treatment of farm workers. “Our dates were handing out those fliers,” he said.

District 8 Councillor Michael Ross, who has been endorsed by the city’s emergency services union, pointed to his efforts to rework a firefighters’ union contract that he considered unaffordable to the city. District 4 Councillor Charles Yancey cited his 30 years on the 13-member council and said he has long supported union issues. “I have stood with you on many picket lines,” Yancey said.

David James Wyatt, a Roxbury Republican and a long-shot candidate for mayor, gave a rambling speech, saying he was “100 percent” opposed to abortion. He stated that he has worked as a Boston schoolteacher and he once spent two weeks as a Teamster working for UPS.

The preliminary, which will winnow the field to two candidates, is slated for Sept. 24. The final election is scheduled for Nov. 5.