Topeka ? Two groups that advocate for tax cuts and against spending increases are joining forces.

The Kansas Taxpayers Network and Kansas chapter of Americans for Prosperity announced Tuesday they are merging.

KTN, based in Wichita, has published annual ratings of legislators based on tax and appropriations bills. Its executive director over the past 15 years, Karl Peterjohn, was elected last month to the Sedgwick County Commission.

“For years, the Kansas Taxpayer Network has worked side-by-side with Americans for Prosperity on numerous fiscal issues,” Peterjohn said. “With our mission and goals being so similar, it only makes sense that our organizations should join at this time.”

Americans for Prosperity was founded by billionaire David Koch, executive vice president and a board director for Koch Industries, based in Wichita. Koch was the Libertarian Party candidate for vice president of the United States in 1980 and is a well-known backer of anti-tax efforts.

AFP-Kansas said it will notify KTN members of the change, and will encourage them to remain as members of AFP.

“Going into the 2009 legislative session, we certainly appreciate the additional support as several tax increases have already been discussed by elected officials,” said AFP-Kansas Director Alan Cobb.

The state faces a $140 million budget deficit in the current fiscal year that could increase to upward of $1 billion next year. Lawmakers convene the 2009 legislative session Jan. 12.