The leaders of President Obama's deficit commission sparked criticism from both sides of the political aisle Wednesday for proposing broad cuts to federal programs.

But the National Commission on Fiscal Responsibility and Reform has also come under attack for its unusual approach to staffing: Many of its employees aren't employed by the panel at all.

Instead, about one in four commission staffers is paid by outside entities, many of which have strong ideological points of view about how to tackle the deficit.

For example, the salaries of two senior staffers, Marc Goldwein and Ed Lorenzen, are paid by private groups that have previously advocated cuts to entitlement programs. Lorenzen is paid by the Peter G. Peterson Foundation, while Goldwein is paid by the Committee for a Responsible Federal Budget, which is also partly funded by the Peterson group.

The outsourcing has come under sharp criticism from seniors' organizations and liberal activists, who say the strategy is part of a broader conservative bias favoring painful entitlement cuts over other solutions. The fears of some liberal groups appeared to come true on Wednesday, when the commission's two leaders recommended significant reductions for Social Security and other social-welfare programs.

Bruce Reed, the panel's executive director, defended the staffing arrangement as fiscally responsible and said the staff includes a broad range of views. Other staffers paid by outside entities include an analyst from the liberal-leaning Economic Policy Institute and a Clinton administration official who now teaches at Johns Hopkins University, he said.

"We've got wonks from across the spectrum who have been working on this issue for years," Reed said. "Every possible voice from left, right or center has a voice on the commission."

But Barbara B. Kennelly, a former Democratic House member from Connecticut who heads the National Committee to Preserve Social Security and Medicare, said the commission's staffing structure is "unprecedented" and casts further doubt on its fairness.

"Taxpayers fund the commission and they should work independently of Washington lobbyists and power brokers," Kennelly said. "This is the type of shenanigans that average Americans are so upset about right now - that money talks and everyone else is left out."

The debate comes as the bipartisan commission nears a Dec. 1 deadline to recommend a plan for lowering the deficit. The panel's two co-chairmen, former Bill Clinton adviser Erskine Bowles and former senator Alan Simpson (R-Wyo.), issued their own recommendations on Wednesday calling for a reduction in Social Security benefits and broad spending cuts for many federal operations.

From the beginning, liberals have complained that the Obama-created commission is tilted in a conservative direction, meaning that it is likely to favor cuts to social programs. (Many conservatives disagree, arguing that Bowles-Simpson proposals to close tax loopholes would result in major tax increases.)

Simpson didn't help relations with liberal groups when he sent an e-mail this summer complaining that the government is "like a milk cow with 310 million tits!" He later apologized for the remark amid demands for his resignation.