TORONTO - The union representing more than 1,500 GO Transit bus drivers and other workers says contract talks with Metrolinx are progressing slowly.

The Amalgamated Transit Union says the company's proposed wage freeze, working conditions and benefits that include two-tiered pensions are among the issues on the table.

ATU Local president Ray Doyle says the company wants to be able to declare some employees as essential workers in the event of a strike -- which the union opposes.

Doyle says the Ontario Labour Relations Board is awaiting a company response before setting a hearing date for the issue.

Setting any strike deadline will have to wait until the essential-workers issue is dealt with.

Contract talks, which resumed Thursday, are set to run through Monday, and are aimed at averting a strike that would idle GO buses but not GO trains.