The union-backed coalition opposing a right-to-work measure raised an additional $152,000, while the group pushing the amendment came up empty-handed in the latest financial reporting period.

Protect Colorado's Future, which is also backing two of its own ballot measures, has raised about $2.38 million so far, about four times as much as the right-to-work advocates.

A Better Colorado, largely funded by Golden-based CoorsTek has raised a total of about $556,000 toward its campaign to pass a right-to-work measure.

The initiative would outlaw arrangements that require workers to pay fees if they are represented by unions. It raised no money in the period from July 3 to July 16.