Updated

New Hampshire frontrunner Mitt Romney is facing attacks from fellow GOP presidential candidates, and on Thursday, also got criticized from the perch in the White House briefing.

After President Obama used recess appointments to add three National Labor Relations Board members on Wednesday, Romney released a television ad in South Carolina hammering the administration over the board's lawsuit against airline manufacturer Boeing, which was looking to build a plant in the Palmetto State. The Romney ad takes a shot at their appointment to the board.

"The National Labor Relations Board, now stacked with union stooges selected by the president, says to a free enterprise like Boeing, 'You can't build a factory in South Carolina because South Carolina is a right-to-work state.' That is simply un-American. It is political payback of the worst kind," the ad says.

Romney's assertion that the appointments mean the NLRB is "stacked with union stooges" drew a rebuttal from Press Secretary Jay Carney, who also noted the candidate's opposition to the recess appointment of Richard Cordray to head the Consumer Financial Protection Bureau.

"I find it a little rich that on this and on the appointment of Richard Cordray to be the nation's consumer watchdog, that the former governor of Massachusetts decided to take a position, in both cases, against the security and protection of working and middle-class Americans," Carney said. "The president made those recess appointments to the NLRB because the NLRB did not have enough members anymore to function."

Romney has regularly attacked the Obama administration on a variety of issues and recently the president's campaign arm has stepped up its hits on Romney. His lead political strategist David Axelrod went after Romney Tuesday but also played down his frontrunner status.

Asked whether the president is paying attention to the early GOP caucuses and primaries, Carney said while Obama is aware of the results from Iowa, he is focused on the presidency.

"He didn't make an assessment of what's going to happen in the race or who he's going to run against," Carney said. "I think he knows from experience, very personal experience, that primaries can play out in a variety of different and unexpected ways. So he's focused right now, honestly, on his job."