The Department of Public Works suspended a foreman accused of shoving and threatening a laborer, and repeatedly using an ethnic slur, during a contentious labor contract vote in which the two disagreed, several witnesses said.

Tony Fischetti, a 30-plus-year employee and department manager, physically and verbally attacked Ricky Falcon Diaz, 42, in the city garage Tuesday as votes on the contract proposal were being tallied, eyewitnesses said.

Fischetti was suspended for 30 days without pay, Public Works Commissioner Anthony Scirocco said Monday, but he would not say why. “”It’s a personnel issue, and I can’t comment,”” Scirocco said.

Fischetti allegedly tried to pick a fight with Diaz by pushing him from behind and taunting him with a derogatory racial term at least three times, witnesses said. The sources spoke anonymously because they said that they were told by managers not to speak to reporters about the alleged incident.

Diaz is of Puerto Rican descent and speaks in heavily accented English. He said in a brief interview that the alleged conflict with Fischetti made him feel uncomfortable.

“”The guy wanted trouble,”” Diaz said.

Sources said that Fischetti became angry when department members of the Civil Service Employees Association voted to approve a two-year contract agreement with the city that included a concession to pay up to $500 a year for health insurance.

Members approved the contract 45-35, they said. CSEA leaders confirmed that members had ratified a contract with the city, but they would not provide its terms.

The city has a zero-tolerance policy for workplace violence. Union leaders would not answer questions about the suspension. Fischetti could not be reached.

This is not the first time Fischetti, who went by the last name Fisher until six years ago, has been accused of bullying. He was convicted in 2005 of second-degree harassment with physical contact, a violation, for head-butting city resident David Bronner during a heated discussion in the City Center. Fischetti was fined $250 and sentenced to 20 hours of community service. Later that year, Bronner alerted media to DPW crews removing trees on Fischetti’s private property in the city.

Last year, the city settled a 2008 racial discrimination suit filed by Henry Smith Jr., who worked as a laborer in the Public Works Department. Smith, who is black, claimed he was subjected to prejudice and a hostile work environment, and was repeatedly overlooked for a full-time job while white employees with less seniority and similar skills were promoted. It’s not known how much the city paid Smith in the settlement.