Updated

Hours after enraging Republicans by appointing the head of the new Consumer Financial Protection Bureau while Congress is out of town, President Obama again bypassed GOP opposition in appointing three people to the National Labor Relations Board.

While union leaders praised the move, Republicans threatened legal action and said Obama is setting a dangerous precedent by ignoring the will of Congress.

Darrell Issa, chairman of the House Oversight and Government Reform Committee, called the appointments "highly controversial" and said they "put the interests of union bosses ahead of job creators and workers."

Sen. Lindsay Graham, R-S.C., said the appointments "may impress the union bosses but will deliver yet another blow to job creation."

Republicans say the NLRB is biased in favor of unions, and some -- including Graham -- had pledged to block Senate confirmation of any board nominees.

The board usually has five members, but has been operating with three. It lost another member this week, leaving it unable to conduct regular business.

"The American people deserve to have qualified public servants fighting for them every day - whether it is to enforce new consumer protections or uphold the rights of working Americans," Obama said when announcing the appointments. "We can't wait to act to strengthen the economy and restore security for our middle class and those trying to get in it, and that's why I am proud to appoint these fine individuals to get to work for the American people."

Obama appointed Sharon Block, Terence F. Flynn and Richard Griffin to the NLRB.

AFL-CIO President Richard Trumka praised Obama's decision to make the appointments in Congress' absence.

"We commend the president for exercising his constitutional authority to ensure that crucially important agencies protecting workers and consumers are not shut down by Republican obstructionism," Trumka said.

Rep. George Miller of California, the senior Democrat on the House Education and the Workforce Committee, said the board is "essential to protecting working families' economic security, and helping ensure that workplaces are productive, fair and safe."

Only the NLRB can enforce workers' and employers' rights under the National Labor Relations Act. But the board has been under GOP fire since last year, when it filed a lawsuit accusing Boeing of illegally retaliating against union members. The case was dismissed last month after Boeing and the union settled their dispute.

Graham said the board "has become an out-of-control rogue bureaucracy" and urged House and Senate committees to "investigate the contacts between the NLRB and machinists union in their complaint against the Boeing Company."

"A congressional investigation to answer questions about NLRB's role, attitude and relationship with the parties is definitely warranted," Graham said. "I'm glad the ridiculous complaint against Boeing has gone away, but there are disturbing questions about possible collaboration between the machinists union and the NLRB against Boeing. These questions must be answered."