Convinced the Senate has reached an impasse on Social Security, a coalition of liberal and labor groups is now trying to kill President Bush's Social Security proposals in the most unlikely of places: the House Ways and Means Committee.

Until now, Ways and Means Chairman Bill Thomas (R-Calif.) appeared to have more than enough votes to draft broad retirement security legislation that included some variation of Bush's efforts to create private accounts funded through Social Security taxes.

But Americans United to Protect Social Security -- a coalition of labor and liberal groups -- identified the committee as an opportunity to "administer the coup de grace" on Bush's approach, according to a PowerPoint presentation by the coalition.

The document identifies eight Republican targets to win over before Thomas completes work on the measure in committee. Labor and liberal activists plan to stage "summer fests," town meetings, district office vigils and leafleting to pressure Republican Reps. E. Clay Shaw Jr. and Mark Foley (Fla.), Nancy L. Johnson (Conn.), Chris Chocola (Ind.), Bob Beauprez (Colo.), Jim Nussle (Iowa), Phil English (Pa.) and Jim Ramstad (Minn.).

"We have them on the run," the document declares.

Ways and Means Committee aides did not respond to repeated telephone calls from The Post.

With a 24 to 17 Republican advantage, Thomas has ruled his committee with an iron fist, moving bills through the panel with little or no Democratic support and the full backing of his party.

But Brad Woodhouse, a spokesman for the anti-accounts group, said overwhelming public opposition to the president's handling of Social Security has changed the equation. Beauprez and Nussle, two reliable Thomas votes in the past, must answer to broader public opinion, since they are both running for governor in their states. And members with large elderly populations in their districts, like Foley, will be "squealers" who will react strongly to grass-roots pressure by pushing Thomas away from Bush's proposals, Woodhouse said.

Foley denounced the characterization as "grade-school grammar."

"I'm not going to relent because this group has decided to choose me as a target," he said.

But if Social Security restructuring does emerge from the committee, it may look considerably different from Bush's plan. Foley spoke highly of Shaw's alternative approach, which would leave the current Social Security benefit intact but add an investment account on top of the existing system. A Nussle aide, speaking on the condition of anonymity because she had not been able to consult the congressman, made it clear that he, too, has yet to embrace the president's proposals.

"He's still weighing the options," the aide said.

The strategy for the Ways and Means members was hatched Friday at a meeting of dozens of liberal and labor groups, including the American Federation of State, County and Municipal Employees; the AFL-CIO; and the National Education Association.

Both supporters and opponents of Bush's Social Security ideas have trained their sights on the Ways and Means Committee, although GOP leaders in Congress and the White House had hoped a Social Security plan would first take shape in the Senate Finance Committee.

But the Finance Committee is stalemated.

Some Senate Republicans outside the committee will push this week for a stopgap measure that would dedicate all surplus Social Security taxes to voluntary personal accounts. That surplus -- totaling $163 billion this year and rising to an estimated $258 billion by 2014 -- would be enough to finance accounts equal to about 3 percent of workers' incomes subject to Social Security taxes. After a decade, the Social Security surplus will begin to decline, choking off the funding source for the accounts and leaving a future Congress to decide whether to continue the program or let it die.

But walling the Social Security surplus off would balloon the federal deficit and force hundreds of billions of dollars in new borrowing. The idea has little support on the Finance Committee, committee and GOP leadership aides said.