The union representing blue-collar workers in the Buffalo Public Schools was granted a preliminary injunction Thursday in State Supreme Court to temporarily bar the district from laying off six employees.

Justice Frank A. Sedita Jr. ordered those workers back on the payroll until Local 264, Civil Service Employees Association, has a chance to see final resolution of its grievance on the layoffs.

The district had announced plans to lay off 21 of the union’s members, but the union sought injunctions on only six of them.

Union President William C. Travis said that’s because a provision in the contract prevents the district from hiring contractors to do work that would displace union members.

The six included technicians who maintain and repair audiovisual equipment, phones, and other equipment.

“These were the guys where contractors are on the job doing the work they did,” Travis said. Contractors have long been in place doing that work, Travis said, but it wasn’t until the layoffs took effect Wednesday that the contractors displaced union members.

Michael J. Looby, general counsel for the Buffalo Public Schools, said that because of changes in technology, much of the work done by employees targeted for layoffs is no longer needed, such as repairing typewriters or mending filmstrips.

The matter will go to a grievance hearing in the next few weeks, then likely will proceed to arbitration, a process that could take several months before a resolution is reached.

Travis said the number of blue-collar workers now headed for layoff is less than half the 21 originally announced. In addition to the six covered by the injunction, three to five employees are likely to take advantage of an early retirement incentive, he said, and the district has delayed the layoffs of four bus drivers.