A Democratic senator asked congressional investigators Monday to examine whether the Social Security Administration's (search) use of taxpayer money to poll the public was legal.

Sen. Frank Lautenberg (search) of New Jersey made the request to the Government Accountability Office (search) after The Associated Press reported Sunday that the federal agency had spent at least $2 million on Gallup Organization (search) surveys since 1998.

Lautenberg said he was troubled by the surveys' inclusion of questions about changes to the retiree benefits program that President Bush has proposed, suggesting those questions were politically motivated.

"The SSA has paid for polling on the president's political agenda," Lautenberg wrote in a letter to Comptroller General David Walker, who runs the GAO.

"SSA is not authorized to poll on such data," he wrote. "The SSA is charged with administering the current program, not evaluating reform proposals."

AP reported that the Social Security Administration hired Gallup under former President Clinton to find out how well-informed people were about the program.

The Bush administration changed the poll in 2003, removing two statements that at least 75 percent of those surveyed earlier had agreed with: "Social Security benefits play a major role in keeping many senior citizens out of poverty" and "Social Security is the largest single source of income for most elderly Americans."

At the same time, the administration added questions that sought to determine when people thought the federal retirement program would run out of money and whether people knew anything about Bush's plan to let workers invest part of their Social Security taxes in private accounts.

The polls did not mention Bush or Clinton. The Social Security agency, now run by Bush appointee Jo Anne Barnhart (search), said it changed the survey on its own, without White House input.

White House spokesman Trent Duffy said he was unaware of any White House involvement in the surveys. He said lawmakers who serve on the congressional committees that oversee Social Security have been briefed by the Social Security agency in past years about the poll results and hadn't objected to the surveys.