Topeka ? A Kansas group, partially funded by a Missouri billionaire and using a bus with an Alabama license tag, started its tour on Friday to spread its message to abolish the Kansas income tax.

“The only way to spur economic growth is to eliminate the income tax,” said Ashley McMillan, president of Kansans for No Income Tax.

The group started its tour in Topeka and planned stops in Leavenworth, Pittsburg and Wichita.

Outside the Statehouse, about 35 people gathered, mostly Republicans and Republican staff members.

State Reps. Richard Carlson, R-St. Marys, who is chairman of the House Tax Committee, and Joe Patton, R-Topeka, spoke, as did Dave Trabert, president of the Kansas Public Policy Institute, and representatives from FairTaxKC.

Gov. Sam Brownback, a Republican, did not appear at the event, but his chief of staff, David Kensinger did. Kensinger said he showed up because he was promised hot chocolate.

Brownback has said he wants to get rid of the state income tax and his administration is working behind closed doors to propose a major tax overhaul for the 2012 legislative session, which starts in January.

Brownback, and Kansans for No Income Tax, say getting rid of the levy will spur economic growth, similar to Texas, which doesn’t have a state income tax. But Democrats and some Republicans say it will force increases in other taxes, cuts in services, or both. They also say Kansas shouldn’t use Texas as an example since Texas lags Kansas in many quality of life areas, such as education, roads and social services.

The issue is likely to be one of the most contentious of the upcoming session.

In the last fiscal year, Kansas brought in about $5.8 billion in tax revenue. Of that amount, about $3 billion came from state income taxes — approximately $2.8 billion from individual income taxes and $225 million from corporate income taxes.

It was reported in recent days that Missouri anti-tax billionaire Rex Sinquefield has contributed to Kansans for No Income Tax. Sinquefield and McMillan have refused to say how much he contributed.

“We enjoy support from folks in Kansas and like-minded folks throughout the United States and we are very pleased with that,” McMillan said.

When asked why the Kansas for Income Tax bus has an Alabama tag, McMillan said, “That’s the bus that was available to us.”

During the 2010 gubernatorial campaign, Brownback was criticized by some for leasing a campaign bus from an Alabama company for use on his campaign.