From the Politico:

The Laborers — like much of organized labor — are deeply opposed to any tax on health benefits. So they’re going up with TV and radio ads on in Montana and North Dakota aimed at Sens. Baucus and Conrad.

A spokesman for the Laborers wouldn’t detail the buy, but said the TV spots will be on broadcast and cable in the two states starting tomorrow and going through next Thursday.

The radio ads will air through July 4th.