NASHVILLE (AP) - State House Republican Caucus Chairman Glen Casada, a staunch opponent of Gov. Bill Haslam's proposal to extend health coverage to 200,000 low-income Tennesseans, on Friday decried what he called "dishonest scare tactics" by a conservative group running radio ads targeting GOP lawmakers.

The Tennessee chapter of the Americans for Prosperity, the organization backed by billionaire brothers Charles and David Koch, this week began running a 60-second radio ad accusing Republican state Rep. Kevin Brooks of Cleveland of "betraying" a promise to oppose President Barack Obama's health care law.

Casada said the groups should spend their time opposing liberal lawmakers and "not dedicated individuals like Rep. Kevin Brooks and the other conservative members of our Republican Caucus who have chosen to seek additional input before making a decision on behalf of their constituents."

Haslam has called a special legislative session to start on Feb. 2 to take up his proposal, which he calls a market-based approach to covering more people and lowering health care costs.

The Republican governor has launched a statewide tour to promote his Insure Tennessee plan, which is causing heartburn among some in his party because it would draw on money available under President Barack Obama's health care law.

"This is not Obamacare," Haslam told reporters after the first stop of the tour in Jackson this week. "This is a different program that puts incentives in there for healthy behavior both on the user side and on the medical care provider side.

"And it won't cost Tennessee taxpayers another dime," he said.

Lawmakers last year enacted a law requiring Haslam to obtain their approval before expanding the state's Medicaid program. Supporters called the measure the "Stop Obamacare Act," and the new radio ads target Brooks and other Republicans who voted for the bill for not dismissing Haslam's p roposal out of hand.

Casada said that while he agrees with the principles of Americans for Prosperity, he disagrees with its campaign against his colleagues.

"The attack ads in districts across the state paid for by AFP are inaccurate, ineffective, and only hurts their reputation within the Tennessee General Assembly," he said. "It saddens me to see AFP hiding behind the curtain and destroying their own credentials through dishonest scare tactics instead of accepting a seat at the table and discussing this important issue face to face."

Andrew Ogles, the organization's state director, said in a statement that Americans for Prosperity "will continue to hold members accountable regardless of their political affiliation for promises they made to their constituents."

"You can put a pretty wrapper on it, but Insure Tennessee is still Obamacare," he said. "If you are supporting Insure Tennessee or pressuring other members to do so, you are supporting Obamaca re."