LOUISVILLE, Ky. — Courting his sometime critics within the gun lobby, John McCain told the National Rifle Association yesterday that Democrats Barack Obama and Hillary Rodham Clinton would both undermine the rights of gun owners.

"If either Sen. Clinton or Sen. Obama is elected president, the rights of law-abiding gun owners will be at risk, my friends — and have no doubt about it," the Republican nominee-in-waiting told a crowd of several thousand.

McCain acknowledged he has been no darling of gun-rights advocates, having pushed through signature campaign finance legislation gun supporters say has muzzled free speech. The Arizona senator has also favored tighter restrictions for buying guns at gun shows.

"Those disagreements do not detract from my long record of support for the Second Amendment and the work we have done together to protect the rights of gun owners ... ," he said.

Nonetheless, McCain said he expected the votes of gun owners in his general election campaign against either Obama or Clinton, the remaining Democratic presidential contenders.

Earlier, after visiting a gun store in St. Albans, W. Va., McCain said the only gun controls he favors are limits to keep guns from people with criminal backgrounds or indications of mental problems.

Meanwhile, his campaign continued to dismiss staff members this week for violating its new ethics policy, as Democrats ratcheted up pressure on McCain advisers for their lobbying backgrounds.

McCain dismissed two staff members Thursday after unveiling the policy, which prohibits staffers from lobbying, representing a foreign agent or participating in outside political groups.

One staffer, Craig Shirley, was dismissed after the Politico reported that he worked for the attack site StopHerNow.com. Another, Eric Burgeson, left Thursday after it was disclosed that he lobbies the federal government on energy policy.

McCain's campaign created the policy following two other forced departures — regional campaign manager Doug Davenport and Republican convention chief Doug Goodyear — for representing the military government in Myanmar.

Democrats seized on the issue, with the liberal group Move

On.org releasing an ad calling for McCain to dismiss top adviser Charlie Black, who until recently was the head of a large Washington-based lobbying firm.

The Associated Press and Washington Post contributed to this report.