US senators have voted against a bill to protect the gun industry after opponents added new restrictions.
Opponents say the ban on military-style weapons does not work
The Republican sponsor of the bill, Larry Craig, began to urge colleagues to stop the changed draft legislation.
The original measure intended to protect manufacturers of weapons from legal action by victims of gun crime.
But Democrats succeeded in attaching amendments to extend a ban on military-style assault weapons and to require checks on buyers at private gun shows.
"I now believe it is so dramatically wounded that I would urge my colleagues to vote against it," Senator Craig said of his bill.
The National Rifle Association (NRA) - a pro-gun pressure group - is also reported to have urged its supporters in the Senate to oppose the bill it had also once championed after the amendments were added.
The Senate Democrats called all their members to Washington for the series of votes, including John Kerry and John Edwards who took a break from their Super Tuesday campaigning.
Aided by some Republican dissenters, they were able to extend the assault weapons ban for another 10 years in a 52-47 vote.
Another amendment was also passed by 53 to 46 to close what critics call the "gun-show loophole" and require people who buy firearms from private dealers at such shows to undergo background checks.
Both measures had been opposed by the bill's backers, including President George W Bush.
Their inclusion led to the change of heart and the entire legislation was rejected by 90 votes to eight.
Legal manufacturers 'punished'
The gun maker-immunity package had been seen as a priority in an election year for the White House, congressional Republicans and other conservative groups as well as the NRA.
All say the gun industry is being sued out of existence for making a legal product, though gun manufacturers have yet to lose a lawsuit.
NRA vice-president Wayne LaPierre said after the vote: "While we will continue to work to save the US firearms industry, we have said from the start that we would not allow this bill to become a vehicle for added restrictions on the law-abiding people of America."
Correspondents say the defeat makes it unlikely that new gun legislation will happen this year. As a consequence, the ban on assault weapons may expire as scheduled in September.
But some Democrats still said the vote was a success.
"The immunity bill was a terrible bill. We're better off at the end of the day than we were at the beginning of the day," Senator Chuck Schumer said.