JEFFERSON CITY - Missouri voters would get another chance to legalize the carrying of concealed guns under a provision adopted Tuesday in the Senate, but hidden handguns would still be prohibited in the state's largest counties.

The amendment added by Republican Sen. Doyle Childers of Reeds Spring would require a statewide vote in November before concealed weapons could be legal. His amendment also would exempt every county with a population of more than 200,000, even if the referendum were approved.

Childers said the state's urban areas should be exempted because they strongly opposed concealed weapons when the proposal was on the ballot in 1999.

"The folks in those counties said they didn't want it," Childers said. "We shouldn't force this upon them. But let the rest of the state enjoy their Second Amendment rights."

Childers' proposal squeaked by on a 15-14 vote. The change would exclude concealed weapons in Jackson, St. Louis and Greene counties and the city of St. Louis. It would allow concealed weapons in Clay and Platte counties.

The legislation, as approved by the House last month, would allow Missouri residents to carry concealed guns statewide. The House version also would change the law without requiring a public vote.

The section of Childers' amendment that would require another statewide vote slipped through without debate as the entire discussion centered on the provision exempting large counties.

Democratic Sen. Ted House of St. Charles objected to his constituents being excluded from the ability to carry a concealed gun. He attached a section that would allow St. Charles County -- with a population of 255,000 -- to be covered by the bill.

But no one objected to the provision requiring the referendum, which had been defeated earlier Tuesday, 15-16.

Sen. Danny Staples, an Eminence Democrat, first proposed the referendum as a way to give the bill a shot at becoming law. Gov. Bob Holden has promised to veto the bill if the General Assembly sends it to him. Many senators were trying to score political points by passing a bill doomed to die on the governor's desk, Staples said.

"I don't see a problem with honest people carrying guns," Staples said. "But this is a political scheme. Some people here who don't support concealed carry will vote for this bill just to force the governor to veto it."

But Sen. John Cauthorn, a Mexico Republican, said the attempt to add a referendum clause was an effort to kill the bill.

"I think it is inappropriate to have a vote on a constitutional guarantee," said Cauthorn, who was elected last year largely by painting his opponent as soft on gun rights.

The changes to the bill were a major setback for gun-rights supporters, who have spent 11 years trying to repeal the law prohibiting concealed weapons. They have consistently opposed another statewide referendum, which failed 52 percent to 48 percent in 1999.

In addition, the National Rifle Association has told leaders of the movement that it does not want to finance another statewide campaign, which cost the group more than $4 million in a losing effort.

Supporters said they would try to pass the bill and have the referendum clause taken off in the conference committee that would resolve differences between the House and Senate versions.

But opponents were gearing up for a filibuster to block the bill. Nearly a dozen potential amendments, most with little chance of approval, were waiting to be debated when senators laid the bill aside. The session concludes Friday.