A pair of Social Security employees told the Democratic Policy Committee that they objected to internal agency documents that directs employees to talk about the system's problems and the need for reform.
"That is a political message and it's not my job as an agency employee to project a political message," said Debbie Fredericksen, who works in the Minneapolis field office and is a union representative.
Mr. Bush hopes to let younger workers divert a portion of their Social Security taxes into personal retirement accounts that are expected, based on historic returns, to be more profitable than traditional government bonds because they could be invested in the stock market.
Democratic opposition to Mr. Bush's plan was expected, but according to the Washington Post, the president is also facing resistance from congressional Republicans.
The newspaper said many House Republicans were reluctant to take any action that might weaken their chances of being re-elected next year, including changes in the politically sensitive Social Security program.
Mr. Bush is scheduled to address congressional Republicans at a retreat outside of Washington on Social Security and other issues on Friday.
Senate Democrats held their session to highlight their opposition to the Bush plan and what they say is the administration's improper use of a government agency.
"We feel that this is a gross misuse and waste of government funds and government personnel," said Steve Kofahl, a claims representative from Seattle and also a union representative.
White House spokeswoman Claire Buchan responded that the agency's actions were appropriate. "The Social Security Administration plays an important role in educating the public and ensuring the American people understand the issues facing Social Security, and we would certainly expect they would continue to play that role," she said.
At Friday's session, several Democrats said they would not support the Bush plan because it undercut the nature of Social Security as an insurance program that guards against poverty in old age.
"Social Security is a lifeline to a decent life," said Sen. Paul Sarbanes, D-Md.
Also objecting was James Roosevelt Jr., grandson of President Roosevelt, who signed the Social Security Act into law.
Separately, Bush's advisers have settled on a proposal for structuring the personal accounts to resemble the Thrift Savings Plan, a tax-deferred retirement investment plan for federal workers similar to a 401(k) plan.
The idea is to minimize risk for people at the outset by offering as few as three to five diversified investment funds.
In the Thrift Savings Plan, federal employees have five investment options, including government and corporate bond funds, a stock fund that tracks the S&P 500, an international fund and other stock funds.
Under Social Security, workers would be enrolled by default in a "life cycle" account, in which investments become more conservative as investors age, if they do not choose one of the other options, according to two officials speaking on condition of anonymity. It would begin with investments that have greater potential for both risk and reward and shift to safer bonds as a worker ages.
The government would be responsible for keeping track of how much money is in each worker's account and give the lump sums to a financial services company to invest, a mechanism aimed at keeping administrative fees low, officials said.
That would mean only a limited profit potential for Wall Street. More money might be available for industry if a second tier of investments were permitted.