Saying that a do-nothing approach to Social Security will mean a big cut in benefits down the road, Sen. Charles Grassley slammed critics of a proposed overhaul of the system at a Tuesday hearing of the Senate Finance Committee.

At the first hearing on the controversial subject, the Iowa Republican said that no action will spark a benefits cut of at least 28 percent by 2041, and he accused Democrats of offering no ideas to keep the system from collapsing.

"Those of you that are bad-mouthing every other suggestion out there, suggest your own plans," he said, according to the Associated Press. His comment followed the suggestion that changes caused by the creation of personal accounts would do more harm than the cuts projected under the existing system.

"Doing nothing is not an option, because doing nothing is a cut in benefits," Grassley said. "Grandpa Grassley gets Social Security, but my granddaughter, when she retires 56 years from now, if we do nothing, is going to get this cut that you're talking about. You can rationalize it all you want to, but by golly, she's entitled to what I got, because her dad and younger people are paying for it."

Sen. Max Baucus, the committee's leading Democrat, said in his opening statement, "We do not have to privatize Social Security in order to save it. Clearly we need to address Social Security's long-run financing. Nobody disputes that. It's clear. But we do not have to make drastic changes."

President Bush's proposal to allow younger workers to invest some of the income from their Social Security payroll tax into private investments is losing support. A Washington Post-ABC News poll released Tuesday showed only 45 percent favored the idea, compared with 56 percent in March. The poll of 1,007 adults conducted last week also found that 64 percent of those surveyed disapproved of the job Bush was doing on Social Security. His overall approval rating was 47 percent, matching his all-time low.