CHARLESTON — Gov. Joe Manchin’s aides filed suit Wednesday against the Obama administration’s coal mining policies as the West Virginia Democrat wages a fierce Senate race against Republican John Raese’s attempts to paint him as a rubber stamp for the president.

Manchin on Wednesday denied any connection between the federal lawsuit and his campaign to finish the remaining two years of the late U.S. Sen. Robert C. Byrd’s term.

The Democratic governor said the suit was already being prepared amid rising concern that U.S. coal policies harm West Virginia’s mining economy months before Byrd died in June. The state hired a Charleston law firm to prepare for a suit and state Environmental Protection Secretary Randy Huffman said in June that litigation was imminent.

“Over the past year and a half, we have been fighting President Obama’s administration’s attempts to destroy the coal mining industry,” Manchin said at a news conference Wednesday at the Capitol.

GOP rival John Raese, a businessman with a shot at a Senate seat the Republicans once considered unwinnable, characterized the suit as flip-flopping by Manchin.

The lawsuit filed by the state Department of Environmental Protection in Charleston federal court names the Environmental Protection Agency and its administrator, Lisa Jackson, as defendants.

It targets EPA policies adopted since Obama took office that are designed to limit the practice of burying streams under excess rock removed while extracting coal at mines. Critics say that practice destroys the environment; the mining industry defends it as an efficient way to produce cheap power and employ thousands in well-paying jobs.

The suit challenges procedures announced during the Obama administration that are designed to reduce the number of permits issued for coal mines in West Virginia, Virginia, Ohio, Pennsylvania, Tennessee and Kentucky.

Since Obama took office, the flow of water quality permits for Appalachian mines has slowed to a trickle.

“People’s jobs are in jeopardy,” Manchin said Wednesday. “We’ve got too much of our economy and too many jobs and people’s families at stake.”

West Virginia Coal Association President Bill Raney praised Manchin’s action. So did Roger Horton, who drives a truck at a Logan County surface mine. Horton said he fears losing his $74,000-a-year job at a moment’s notice.

Manchin invoked Byrd’s legacy during his news conference. He pulled out a copy of the U.S. Constitution and quoted the 10th Amendment, which deals with states’ powers. Byrd was well known for carrying a copy of the Constitution and quoting from it.

And Manchin was emphatic in denying his campaign had anything to do with the suit, which he said has been in the works since April.

“I’m a governor first. That’s my first and foremost job,” Manchin said.

Huffman said Manchin decided to sue in recent weeks after months of waiting for the EPA to deny a permit in a way that invited a legal challenge.

U.S. EPA officials said West Virginia hasn’t engaged in a meaningful discussion of sustainable mining practices that protect water. The agency said its most recent policy, issued in April, makes sure that permits are reviewed to protect people and the environment from water pollution.

However, Raese’s campaign said that the suit represented another example of the governor trying to distance himself from Obama.

“He proceeded to take absolutely no legal action against the EPA’s regulations until he dropped behind in the polls just weeks before the election,” spokesman Kevin McLaughlin insisted in an e-mail.

The lawsuit is the latest twist in the race to replace Byrd, who served more than a half-century on Capitol Hill. President Barack Obama didn’t carry the state in 2008 and stricter regulation of the mining industry has not improved the president’s standing in the No. 2 coal producing state.

Manchin can count on support from organized labor, the coal association and the U.S. Chamber of Commerce.

But the National Republican Senatorial Committee is spending $1.3 million on ads attacking Manchin. And state Republicans are preparing an effort to plant 2,500 yard signs across West Virginia reading: “Obama Says ‘Vote Democrat.”’