Gun control advocates are expecting the worst Wednesday when the House votes on a provision that would allow national park visitors to carry loaded and concealed firearms.

The Senate added the gun language — a legislative priority for gun rights advocates and Sen. Tom Coburn , R-Okla. — before passing a credit card regulation bill (HR 627) bill and sending it back to the House for final action. The House plans a separate vote on the guns provision before voting to clear the legislation.

A hastily assembled coalition of gun control advocates, park rangers and environmental groups joined House members Tuesday afternoon to urge the House to reject the Senate provision.

“We’re definitely working to try to stop it,” said Daniel Vice, attorney for the Brady Center to Prevent Gun Violence. “It’s always difficult when you have an amendment attached to a completely different bill with relatively no debate. It’s an end run around the system and we think a very dangerous one.”

The adoption of Coburn’s amendment to the credit card bill on May 12 caught gun control supporters by surprise, Vice said.

Coburn argues that park visitors should be able to defend themselves and notes that homicides, rapes, robberies, kidnappings and other assaults occur in national parks every years.

In January, President George W. Bush reversed a federal rule that banned loaded firearms from national parks. A federal judge imposed an injunction against the Bush rule last month.

The Senate provision would ban the Interior Department from prohibiting visitors to national parks and wildlife refuges from carrying firearms if they comply with state laws. Only Illinois, Wisconsin and the District of Columbia do not allow individuals to carry firearms.

President Obama’s election and Democratic gains in last year’s congressional elections have not translated into legislative victories for gun control advocates. There has been no action to renew an expired federal restriction on assault-style weapons, and in February, Senate Democrats helped provide a majority for adoption of an amendment that would ease restrictions on gun ownership in the District of Columbia. The Senate provision has stalled House action on a bill (S 160) that would provide the District with full voting representation in the House.

Gun control advocates expect the Democratic-controlled House to go along with the national parks firearms provision, said Ladd Everitt, communication director at the Coalition to Stop Gun Violence.

“I think this reveals the power of the [National Rifle Association] as a special interest lobby, but I think it also reveals that the Democratic Party has changed,” Everitt said. “They are not your mother’s Democrats. The Democrats are carrying the NRA’s water as much as the Republicans.”

Erich Pratt, director of communications at Gun Owners of America, agreed that Democrats are being careful out of respect for the gun lobby’s power. He said his group has been working for a while to get the national parks provision language through Congress and is excited that it is now part of legislation apparently headed toward enactment.

“People have been raped, murdered, attacked by wild animals,” Pratt said. “Whether you’re in national parks or Washington, D.C., it’s just not right to tell people that you can’t protect yourself and we will punish you if you try to.”