Missouri Lt. Gov. Peter Kinder filed a lawsuit Wednesday over the federal healthcare overhaul, accusing Congress of overstepping its authority, trampling on state sovereignty and attempting to interfere with consumers' health decisions.

Numerous states have challenged the federal healthcare overhaul since it was signed into law last March. Missouri's lawsuit — filed by Kinder in his personal and official capacities and by three other residents — asserts that the federal government cannot compel people to buy a product and cannot require state officials to participate in enforcing a "federal scheme."

Kinder, a Republican, said in a written statement that the federal healthcare legislation is unconstitutional and would make healthcare more expensive.

"Many Missourians will lose the options for health insurance they currently enjoy," Kinder said. "Missourians have less healthcare coverage after the federal law was passed than they did before it was passed."

The federal healthcare law expands health insurance to 30 million people. It allows parents to keep their children on their insurance plans until age 26. It expands Medicaid coverage. And starting in 2014, most Americans will be required to have health insurance or face tax penalties.

The Justice Department has argued in other lawsuits that the federal healthcare law fits within Congress' authority to regulate interstate commerce and to provide for the general welfare. It argued that decisions to opt out of health insurance have consequences for everyone.

U.S. Department of Justice spokeswoman Tracy Schmaler said Wednesday that it will defend the federal healthcare law from challenges over constitutional or other grounds.

"We are confident that this statute is constitutional and that we will prevail," Schmaler said.

In his lawsuit, Kinder contends the federal healthcare law could cause Missouri to raise state taxes to pay for the expanded Medicaid program and that it improperly affects the compensation of state officials by making changes to the state healthcare plan. He also contends the healthcare law is unconstitutional because he says it interferes with Missourians' personal healthcare choices.

Missouri Attorney General Chris Koster, who left the Republican Party and became a Democrat in 2007, has said he's monitoring the various legal challenges to the healthcare law, but he has not filed his own lawsuit. His spokeswoman, Nanci Gonder, did not immediately return a call Wednesday seeking comment.

The other plaintiffs in the lawsuit are Samantha Hill, 21 of Holden, Dale Morris, 65, of St. Louis and Julie Keathley, whose late husband was an aide to Republican former Gov. Matt Blunt. The suit was filed in U.S. District Court in Cape Girardeau.

It names as defendants U.S. Treasury Secretary Timothy Geithner, Health and Human Services Secretary Kathleen Sebelius, Attorney General Eric Holder and Labor Secretary Hilda Solis.

Kinder said for months that he planned to sue over the healthcare law. Initially, Kinder said he planned to join a Florida lawsuit of which 20 other states have since joined. Later, Kinder said he would sue by the end of April.

Kinder is raising private money to pay for his lawsuit, but has not released a list of donors. Kinder spokesman Gary McElyea said donations were sought from individuals through Healthcare In Action, a private entity set up for the lawsuit. McElyea said some donors will be made public.

The Missouri Democratic Party criticized both the lawsuit and the uncertainty over who was funding it.

"Peter Kinder has decided it is time try to block healthcare coverage for hundreds of thousands of Missourians. The real question that remains is: Who is helping him fund his frivolous lawsuit?" said Democratic Party spokesman Ryan Hobart.

Missouri lawmakers critical of the federal healthcare law also have referred to the Aug. 3 ballot a measure that seeks to defy the law by declaring that people and employers cannot be compelled to heave health insurance nor penalized for covering their own healthcare bills.

The ballot measure has been challenged in a separate lawsuit filed in state court. A Cole County judge has scheduled a hearing Tuesday for that lawsuit.