House Democrats sought reassurances Thursday that Republicans wouldn't try to bypass them by adding private investment accounts to Social Security (search) legislation at the last moment.

"This chairman has no interest, on a subject of this importance, in playing 'gotcha' in any way," Rep. Bill Thomas (search), R-Calif., who heads the Ways and Means Committee, answered at the start of another hearing that quickly degenerated into partisan bickering.

"I have an interest in producing a product ... which is a responsible one and should elicit bipartisan support at the end of this legislative process," Thomas said.

The question was raised by Rep. Richard Neal, D-Mass., based on what one of his aides said were rumors circulating on Capitol Hill.

Thomas has been trying to push a Social Security overhaul, President Bush's top domestic priority, by expanding it into a larger legislative package focused on retirement security. But he hasn't been insistent on the personal accounts favored by Bush, which would allow workers below the age of 55 to begin investing a portion of the payroll taxes (search) currently used to fund retiree benefit checks.

While that openness has pleased some members of the panel, it has prompted fears among others who suspect the accounts may be added in a House-Senate conference committee just before the broader package is put to a vote in the chambers, where the Republicans enjoy sizable majorities. Thomas is aiming to have his own committee vote on a bill by early June, although aides have said that timetable may slip.

"Might you be willing to clarify for members of this committee, and to those who are watching this committee, that you will not add private accounts to a conference report and will not include it in a House-passed bill?" Neal asked Thomas.

Thomas twice declared that he didn't want to play "gotcha" and he defended his decision to expand the focus of the hearing, saying it would be a "derogation of duty" not to consider items beyond Social Security amid evidence Americans are not saving enough for retirement.

The panelists testifying before the committee Thursday argued that existing tax-favored retirement accounts such as 401(k)s (search) are not being used by the low-income workers most in need of retirement assistance. The panelists suggested Congress focus on vehicles to ensure low-income workers save for retirement as widely as people earning more money.

Among the suggestions are automatic enrollment in the accounts, and investment in diversified investment vehicles to ensure the best possible return.

After Thomas lauded that advice in his opening statement, the panel's top Democrat, Rep. Charles Rangel, D-N.Y., slapped him down, saying the committee's rightful focus should be on ensuring the solvency of Social Security.

"I wish the chairman had a written statement so I could follow more clearly where you want to take the committee," Rangel said as Thomas leaned back in his chair next to him.