On Thursday, the president will direct the Labor Department to revamp its regulations to require overtime pay for several million additional fast-food managers, loan officers, computer technicians and others whom many businesses currently classify as “executive or professional” employees to avoid paying them overtime, according to White House officials briefed on the announcement.

Mr. Obama’s decision to use his executive authority to change the nation’s overtime rules is likely to be seen as a challenge to Republicans in Congress, who have already blocked most of the president’s economic agenda and have said they intend to fight his proposal to raise the federal minimum wage to $10.10 per hour from $7.25…

Mr. Obama’s authority to act comes from his ability as president to revise the rules that carry out the Fair Labor Standards Act, which Congress originally passed in 1938. Mr. Bush and previous presidents used similar tactics at times to work around opponents in Congress.

The proposed new regulations would increase the number of people who qualify for overtime and continue Mr. Obama’s fight against what he says is a crisis of economic inequality in the country. Changes to the regulations will be subject to public comment before final approval by the Labor Department, and it is possible that strong opposition could cause Mr. Obama to scale back his proposal.