They argue the bill has been watered down because of pressure from the National Rifle Association (NRA), reports CBS News Correspondent Diana Olick.
The House is considering a bill passed by the Senate that would, among other things, crack down on sales at gun shows and require safety devices on all new handguns.
The legislation was prompted by the April 20 massacre at Columbine High School, where 12 students and one teacher were gunned down by shooters Eric Harris and Dylan Klebold.
Democrats are expected to continue the war of words over guns Friday, saying that Republicans weakened the Senate gun control bill.
"The Republican bill before the House is a sham. ItÂ's a fraud," said Senate Minority Leader Tom Daschle, D-SD.
"When the NRA speaks, Republican bill writers listen," said House Minority Leader Richard Gephardt,D-MO.
The Senate bill would require:
- mandatory background checks on all firearms transactions at gun shows and pawn shops
- safety locks or other devices to be sold with all new handguns
- a ban on the importation of high capacity ammunition clips
- mandatory prison sentences for felons committing crimes with guns and
- a lifetime ban on gun ownership for any juvenile convicted of a felony
But the number-two Republican in the House says the bill wasn't watered down, denying that it was at all dictated by the NRA.
"Nobody wrote this bill except gravely concerned members of Congress in the committee, listening to their colleagues, and worrying about the children of this nation," said Rep. Dick Army, R-TX.
Speaker of the House, J. Dennis Hastert, said he's no longer rallying Republican leadership behind one stiff proposal, but waiting for the House to work its will because there are simply too many differing opinions.