Yale will begin subcontracting service and maintenance work in a new research building near the School of Medicine next week, angering union leaders who said it could set back contract talks and intensify tensions between Yale and the unions.

The plan to outsource work in the Congress Avenue Building, or CAB, comes as Yale and its two largest unions, locals 34 and 35, continue negotiations for new contracts. Union leaders said they believe outsourcing work shows a lack of commitment by the University to job security in Local 35, which represents nearly 1,100 service and maintenance workers. Yale officials said CAB was outsourced because there is no current agreement on best practices that would give the union work that would otherwise be subcontracted.

Local 35 President Bob Proto said the plan to subcontract work will have a “tremendous impact” on contract talks. He characterized the University’s decision as a “tactic” that “rolls the clock back” on progress made in bargaining sessions since the last negotiations.

“This is just another way of Yale indicating that they want to have a war here,” Proto said. “Now they’re playing a roulette game with regards to job security.”

Yale spokesman Tom Conroy said the move did not violate any contract provisions and should not have surprised union leaders.

Job security and subcontracting have long been major issues of dispute between Local 35 and the University. In 1996, the last time the Yale and locals 34 and 35 negotiated contracts, the two sides spent 13 months clashing over concerns including subcontracting. Eventually, a new provision was made in the Local 35 contract, allowing the University to subcontract any work, in exchange for job security guarantees. The provision is effective through 2006.

When negotiations began this year, however, University leaders offered to allow Local 35 to staff new buildings in exchange for certain performance and management standards. The two sides reached a tentative agreement in April that would give Local 35 the right to work in all new buildings provided that the two sides agreed to and meet best practices work and management standards.

But the agreement also required that the work be outsourced if no best practices agreement had been established by the time each new building opened.

Conroy said discussions on best practices began in April at a time when University officials were still hopeful that a contract could be settled by the end of the school year. He said that because there is no current best practices agreement and the building is becoming operational, it must be staffed in other ways.

Conroy said union leaders understood this agreement.

“There certainly should be no reason on their part that they should be surprised,” Conroy said. “We’ve never reached an agreement on best practices that would result in [Local 35 members] getting work.”

Proto said the decision came as a “shock” since Local 35 members had been given a walk-through of CAB.

Proto said the subcontracting of CAB sends a message that Yale is not committed to showing respect for its workers.

“The University is trying to pick issues that would prompt a fight,” he said. “It’s going to get people more angry than they are now.”

Conroy said he believes the unions have turned their attention away from settling a contract and are absorbed in the organizing drives of hospital workers at Yale-New Haven Hospital and the Graduate Employees and Students Organization.

“It all comes back to the fact that they chose to focus on the hospital and the graduate school,” he said. “We wait patiently for the unions to change their focus and turn to the job of settling [new contracts].”

This summer, despite the fact that the two sides had not yet worked out best practices agreements, the University agreed not to subcontract work in the newly renovated Timothy Dwight College. Union leaders called TD an “egregious example” since Local 35 has always done work for the building.