By Susan Guyett

INDIANAPOLIS (Reuters) - Indiana Republicans voted on Wednesday to begin fining Democratic state representatives $1,000 per day if they stay away from full sessions in a boycott aimed at delaying action on proposed right-to-work legislation.

Republicans, who hold solid majorities in the state House and Senate as well as the governor's mansion, have pressed for Indiana to join 22 other states with right-to-work laws arguing that it would attract jobs to the state.

Indiana would be the first state in the industrial heartland of the United States with such a law, which could permit employees to work at union-represented workplaces without paying dues or joining the union.

The state is home to union and non-union auto industry plants and critics of the measures call them union-busting. Most states with right-to-work laws are in the South or West, areas of the U.S. where the auto industry has been adding production.

Democrats on Wednesday held a rally in the Indiana House rotunda instead of attending the legislative session, leaving too few representatives to conduct regular business.

House Minority Leader Pat Bauer said Democrats planned to fight the fines in court. Democrats are still fighting fines imposed last year when they left Indiana for five weeks over similar labor issues.

House Democrats fled Indiana to neighboring Illinois last year to avoid voting on a similar right-to-work bill and other legislation they viewed as anti-labor and anti-public education. The bill died, and other bills were altered.

In the current year, 44 amendments have been proposed for the right-to-work legislation. Democrats want the question to be decided by state referendum and have asked for time to craft a proposal.

Measures to curb the powers of public-sector and private sector unions were introduced in several midwestern states last year after gains in the 2010 elections gave Republicans control or strengthened majorities.

The impact was notable in Wisconsin and Ohio, both potential swing states in the November election, as well as in Indiana.

In Wisconsin, Republican proposals to limit public-sector union powers sparked extended protests at the Capitol in Madison, but were ultimately adopted.

The polarizing debate in Wisconsin led to efforts to recall state senators in both parties last year, and Democrats on Tuesday turned in more than 1 million signatures to support a drive to force Republican Governor Scott Walker into a recall election.

In Ohio, the Republican-led legislature approved changes to the powers of public-sector unions, but voters turned back the effort in a referendum last November.

(Reporting by Susan Guyett; Editing by David Bailey and Cynthia Johnston)