* Obama calls it 'right to work for less money'
* Up to 10,000 expected at protests
* No sign Republicans will back off
* Michigan more important to unions than Wisconsin
By Bernie Woodall
LANSING, Mich., Dec 10 (Reuters) - Republicans are likely to approve contentious "right-to-work" measures in the union stronghold of Michigan on Tuesday despite thousands of people converging on the state capital to protest proposed laws they say would lower wages and hurt workers.
Organizers expect as many as 10,000 unionized workers to go to the state capital of Lansing on Tuesday, some taking a day off from jobs, to demonstrate against the laws which would make union membership and dues payment voluntary.
President Barack Obama waded into the debate during a visit to the Daimler Detroit Diesel plant in Redford, Michigan on Monday, criticizing the Republican "right-to-work" effort.
"What they're really talking about is giving you the right to work for less money," Obama said to loud applause from workers. His visit to Michigan was scheduled before the issue erupted.
Michigan is far more important to the labor movement than Wisconsin, where a similar battle was fought with unions over the last two years. Michigan is the home of the U.S. auto industry, with some 700 manufacturing plants in the state, and is where the United Auto Workers union was born.
While the new laws are not expected to have much immediate impact because existing union contracts would be preserved, they could, over time, further weaken the UAW, which has already seen its influence wane in negotiating with the major automakers.
Both Democratic and Republican sources said approval of Michigan becoming the 24th "right-to-work" state is almost assured as Republicans have majorities in the legislature. Governor Rick Snyder has vowed to sign the legislation.
So-called right-to-work laws would prohibit closed union shops that compel workers to pay union dues, which for members of the UAW is equal to their pay for two hours a month.
On Monday, only a handful of protesters were seen outside the Capitol building as the legislature was not in session.
Last Thursday, when the measures were rushed to preliminary approval in both chambers of the legislature, a crowd of protesters rallied outside the Capitol and several hundred got inside. Some people were arrested and the Capitol was temporarily closed to visitors for safety reasons, according to Michigan State Police Inspector Gene Adamczyk.
Adamczyk said his officers along with local fire marshals will work to keep the Capitol open throughout the legislature's work day on Tuesday, but security was expected to be tight.
Jase Bolger, the Republican House Speaker, said he expects two bills to pass the House on Tuesday covering public and private sector unions. He dismissed Democratic charges that the "right-to-work" issue has not been properly aired with public hearings.
"We've debated this in the legislature for almost two years now," Bolger said.
Michigan Democratic leaders accused Bolger and the Republicans of ramming the "right-to-work" laws through during a "lame duck" session of the legislature.
Political analysts have said bills were rushed to a vote last week because Republicans lost five Michigan House seats in the November election and their majority would shrink in January, when the new legislature is seated.
"We're under no illusions that we are likely to stop this thing," said Democratic House member Tim Greimel, who will be the House minority leader in the new year. "But the least the people of Michigan deserve is some semblance of a deliberate process."
Michigan's Democratic U.S. Senator Carl Levin and six Democratic congressmen met with Snyder on Monday and urged him to veto the "right-to-work" laws.
The governor said he would seriously consider their appeal but his office later issued videos showing workers who support "right-to-work" and there was no indication he would back off.
Michigan has the fifth highest percentage of unionized workers in the United States at 17.5 percent and the Detroit area is headquarters for General Motors Co, Ford Motor Co and Chrysler.