WASHINGTON (CNN) - Members of the Senate Democratic Policy Committee Friday assembled an array of witnesses to air concerns over what is publicly known about the Bush plan to change the Social Security System by including individual investment in the stock market.

Earlier this week, Republican senators met with Bush on the concept, but emerged from the White House meeting saying the president offered few details beyond his public mantra of creating private accounts for younger workers.

Democrats noted none of the Republicans invited to Friday's meeting had chosen to appear.

"The administration in my view is once again manufacturing a crisis," said committee member Sen. Paul Sarbanes of Maryland. "There is no crisis in the Social Security system. The system is not on the verge of bankruptcy."

More sharply critical was the committee's chairman, Sen. Byron Dorgan of North Dakota. "They would propose that we reduce benefits in the Social Security program," he said, "I think that is a horrible, horrible public policy to pursue, and my hope is that Congress will reject that."

James Roosevelt, the grandson of the president who ushered in the Social Security Act in 1935, testified it is "a disgrace and an insult to his memory" to use Franklin Delano Roosevelt's legacy in support of the Bush concepts, as was done in recent advertising.

Citing a handwritten document handed down to him that lists FDR's principles behind Social Security, the younger Roosevelt said, "Its success lies in the fact that it's an insurance plan, not an investment plan or a welfare plan."

Kenneth Apfel, who was Social Security commissioner from 1997 through the end of the Clinton administration, predicted a crisis if stocks were to collapse under the Bush plan, taking benefit payouts with them.

"I would hate to see a future U.S. Social Security commissioner urging American older workers to just keep working until the markets come back," Apfel told commissioners. "We don't really know how long that wait might be."

He said "Social Security ought to be, and represent, a foundation of support that can be counted on in retirement, no matter what happens to the market."

The Democratic panel also heard from two career workers with the Social Security Administration who expressed alarm that they have been asked to promote the Bush plan in public speeches and in exchanges with beneficiaries.

The staffers said they considered inappropriate a recent benefits statement mailed to many taxpayers saying, "Action is needed soon to make sure the system is sound."

Democratic senators issued a statement saying they plan to introduce legislation titled "The Stop Government Propaganda Act," to prohibit the use of taxpayer money for misleading or inaccurate messages.