OTTAWA - The federal government has appointed a special mediator in hopes of breaking the stalemate in the contract talks at Canada Post.

Labour Minister MaryAnn Mihychuk offered the mediation service Wednesday night as both sides in the labour dispute remained far apart, with a strike mandate set to expire.

Mihychuk says she expects both sides to work with the mediator to avoid a work stoppage.

The Canadian Union of Postal Workers has until midnight Thursday to serve the Crown corporation with a 72-hour strike notice.

As of late Wednesday, the union was accusing Canada Post of stalling the talks by continuing to make unacceptable demands.

Should Thursday's last-ditch mediation efforts fail, the union could give formal notice of a strike that would disrupt mail and parcel deliveries by Monday.