PORTLAND, Maine (AP) Opponents of a $1 billion power corridor in western Maine have collected roughly 100,000 signatures for a referendum drive to defeat it.

The petitions were being delivered to the secretary of state’s office Thursday afternoon for a second referendum attempt. Opponents previously collected more than 63,000 signatures for a “People’s Veto” referendum that was deemed unconstitutional by the Maine Supreme Judicial Court.

Three conservation groups are suing to stop the project.

Supporters say it would provide a conduit for up to 1,200 megawatts of Canadian hydropower to reach the regional power grid, reducing greenhouse emissions and stabilizing energy costs in the region.

Critics say the benefits are overstated and that the project would destroy unspoiled wilderness.