The Board of Aldermen held a contentious meeting Thursday about claims of bias against minority construction workers on city building projects.

Three aldermen have proposed a resolution calling for a formal hearing on job security and hiring in city construction projects, and yesterday’s meeting featured impassioned testimony from minority construction workers who said they lack job security and have not been treated fairly by contractors. But a representative of the city’s commission on equal opportunities denied that minority workers have been discriminated against.

Alan Felder, the president of nascent activist group Man-Up, criticized rules on construction jobs in the city’s labor agreements, which stipulate that workers can be fired after they have completed 25 percent of the hours they are contracted to work. He said this leaves workers unable to complete the number of hours required to receive health and retirement benefits.

“You need 100 percent of the required hours, not 25,” he said.

Nicole Jefferson, executive director of the city’s Commission on Equal Opportunities, followed Felder. Jefferson said people were wrong to attribute hiring and firing decisions to questions of race and challenged workers to substantiate their claims.

“People are constantly laid off, and it’s not always about race,” she said. “Write it down. Who is it? You can’t give me a name? Not one name or what happened? Who can fight that case? God? Give me something to help you.”

Her testimony, and that of Ben Cozzi, the president of a local union, was marked by loud interruptions from the audience, who disputed their claims that hiring practices in the city are fair.

Ward 2 Alderwoman Joyce Chen ’01 said she had heard from her constituents that employers are splitting the 25 percent requirement between different workers and laying them off before they are legally allowed to do so.

“That’s right,” members of the audience said.

Chen asked Cozzi if this has happened.

“No,” he said.

“Yes!” shouted audience members.

Ward 13 Alderman Alex Rhodeen asked Jefferson if she thought contractors were meeting the minority hiring standards set out by the city. Jefferson read a list of statistics from different contractors that she said showed that contractors hired more minorities than the required 25 percent.

“We have the highest minority hiring in the state,” she said, adding that the city keeps a detailed file on every single person working on construction jobs around New Haven.

But Rory Kelman, a construction worker, said in his testimony that he did not think the numbers would hold up under scrutiny.

“I don’t buy the numbers,” he said. “Nobody’s finding out who’s on the job.”

Ward 11 Alderman Robert Lee said the real issue was job security for New Haven workers. He said he was concerned about the longevity of construction jobs, more than the number of hours each worker spends on the job per week.

“You know what they say about minorities: last one in, first one out,” he said, drawing loud applause from the audience. “I don’t want to see ours be the first to go. And if it’s not there, I’ll start working on getting it there.”

Kelman made similar remarks, explaining that it is not uncommon for someone to be in the construction trade for 30 years but, because of the lack of job security, only work for the equivalent of 15. This is not enough to meet the requirements for retirement benefits, he said.

Many people praised Jefferson and the Commission on Equal Opportunities for the work they have done to ensure that more minorities are hired.

“The CEO, everybody [involved], Nicole — I applaud them, because without the CEO I would not be where I am at,” said McCraig Griffin, who described himself as a laborer.

Everyone who testified said they favored more hearings on the issue. Phil Cooper, another construction worker, said he is willing to support whatever policy the board decides on,

“Whatever you do, you’re the chiefs,” he said. “I’ll go along with it.”

Ward 6 Alderwoman Dolores Colon, chair of the Municipal Services Committee, said the committee will meet on Saturday to discuss whether to move forward with more hearings and, perhaps, future legislation on the issue of minority hiring.

The resolution was proposed by Chen, Ward 23 Alderman Yusuf Shah and Ward 30 Alderwoman Michelle Edmonds-Sepulveda.