Employees in the 300-member union of Harvard maintenance workers, who have been involved in contract negotiations with the University since December, last night voted to initiate a wildcat strike today.

About 200 members of the Maintenance Trades Council, which combines five separate union locals, voted to join picket lines that Carpenters' Local 40--one of the member unions--was expected to form today outside Holyoke Center and other locations.

The 56-member carpenters' local decided it would strike today after the University ordered five of its members to report to work today as painters and lampers, rather than carpenters.

The issue of University re-classification of employees' trades has been a key point in negotiations between the trades council and the University.

Edward W. Powers, associate general counsel for employee relations, said yesterday Harvard has asked carpenters to "help some of the other trades where we have more work than we have people."

"We can't determine who is to do what on the basis of what union they are in," Powers added.

James P. Costello, general agent for the Carpenters District Council of Boston and Vicinity and spokesman for Local 40, said yesterday re-classification of union members threatens their job security and makes them uncomfortable, working in unfamiliar trades.

Costello said he was in the process of trying to avoid a walk-out. "Serious commitments are being made by individuals," he said.

"I don't feel the University as a whole is being completely out front with us," Costello added.

The maintenance workers' last contract ran out on December 7, but the University and the trades council have continued to extend the contract by mutual consent. As negotiations stretched into March, a federal mediator was called in who attended the last two bargaining sessions.

Under the standing agreement between the trades council and the University, the union must give 30 days notice before calling its members out of work. Workers are expected to characterize any strike action today as independent of union direction.

The University could file an unfair labor practice complaint with the National Labor Relations Board today, seeking an injunction, if a strike takes place.

Powers said yesterday workers who stage a job action under the terms of the current contract are also "subject to discharge by the University."

Negotiations with the union have covered wages, vacations, and employee health plans, as well as job reclassification.