MADISON, Wis. - The state Assembly is preparing for what's shaping up to be the last legislative debate on Republicans' polarizing mining legislation.

The Assembly's Republican leaders have scheduled debate to begin at 9 a.m. Thursday, a rare start time for the chamber. Republicans anticipate minority Democrats will try to delay the final vote and hope the early start will help them avoid an all-night session.

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. Republican supporters insist the mine will create thousands of jobs. Opponents counter the bill would open the door to devastating pollution.

Assembly approval would send the bill to Gov. Scott Walker for his signature, the last step before it would become law.