The House Oversight and Government Reform Committee subpoenaed the Environmental Protection Agency on Friday for documents concerning a controversial Alaska mine, the Washington Examiner has learned, in a move that points to increasing scrutiny of the agency’s intention to block the project.

At issue is the EPA’s signal to veto a key Clean Water Act permit for the Pebble Mine, a proposed copper-and-gold mine in the watershed of southwest Alaska’s Bristol Bay. The mine has drawn intense Capitol Hill lobbying, pitting Democrats, native Alaskan tribes, environmentalists and commercial fishermen against Republicans and the industry.