Republicans who control the state Assembly say they are confident a mining bill will protect the environment and bring jobs to Wisconsin despite Democrats who say it will harm air and water quality.
The Assembly began debate of the measure Thursday. It was expected to pass in the late afternoon.
Republican Majority Leader Scott Suder calls the measure "perhaps the most important jobs bill we've seen in a great long while." He says the iron ore mine near Lake Superior could be operational within three to four years.
The bill would loosen the state's mining regulations to help Gogebic Taconite dig a huge open-pit iron mine just south of Lake Superior.
Assembly approval would send the bill to Gov. Scott Walker, the last step before it would become law.