Union workers from a local carpenters' union are protesting a renovation project on the Harvard-affiliated Smithsonian Center for Astrophysics.

Carpenters' Local 40 will continue picketing outside the construction site at 60 Garden St. today. The union charges that Harvard's general contractor for this project is employing illegal labor practices.

In addition, the union's leaders are accusing Harvard of reneging on oral agreements reached during past contract negotiations.

Members of the union have distributed leaflets over the past week which claim that Harvard has been hiring non-union general contractors who employ illegal labor practices.

The flyer says that C.E. Floyd, the general contractor of the Smithsonian Center project, pays inadequate wages, provides few or no benefits and regularly violates tax, insurance and legal obligations.

The flyer also accuses the University of hiring other unnamed contractors who fail to abide by labor laws.

These firms, according to the flyer, escape the legal restrictions by treating their employees as independent contractors.

Doing so allows the firms to avoid paying Social Security and Medicare taxes, state and federal unemployment taxes, workers' compensation insurance and other legally mandated payroll costs.

According to Mark Erlich, business manager for Carpenters' Local 40, Harvard is "subsidizing an underground economy."

"There is very little difference between purchasing contracting services in this way and purchasing hot boom boxes out of the back of a pick up truck," Erlich said.

University officials denied any knowledge of the illegal practices.

"We expect the contractors to be in compliance with federal and state regulations," said Merry Touborg, a spokesperson for the University's Office of Human Resources.

And Chuck Floyd, C.E. Floyd's owner, also said he was unaware of illegal practices by his subcontractors.

Additionally, he denied that it was his place to monitor all the activities of his hundreds of subcontractors.

"It is not my responsibility to audit everyone who works for me," Floyd said. "I have contracts that require them to abide by the law. I assume they are all following it properly, but there is no way for me to know."

Floyd said that the union's claims are unfounded and charged that the union is merely trying to intimidate Harvard into hiring union workers.