Detroit's bankruptcy is hitting a courtroom for the first time as a judge considers what to do with challenges from retirees who claim their pensions are protected by the Michigan Constitution.

The city wants U.S. Bankruptcy Judge Steven Rhodes to put a stop to lawsuits in other courts, especially after an Ingham County judge said state officials ignored the constitution and acted illegally in approving the bankruptcy last week.

Protesters are planning to gather outside the Detroit federal courthouse, while lawyers for some of the thousands of creditors arrive early for seats inside.

The judge won't be diving yet into Detroit's billions of dollars of debt. The bankruptcy case is expected to last a year or more.