A cutting tool with first and second pivoted shearing blades has a guide member mounted to the first blade for transverse movement relative to the first blade and toward and away from the second blade. The guide member has at least one transverse restraining surface that confronts a transverse guided surface of at least one of the distal blade portions during cutting to resist axial separation of the cutting edges away from the cutting plane. In some embodiments, the guide member is actuated by placing the workpiece between the blades. Alternatively, the guide member is actuated by relative pivotal movement of the blades.