Gov. Bill Ritter is poised today to sign a landmark clean-air bill aimed at upgrading aging Front Range coal-fired power plants to run on natural gas, The Denver Post reports.

While sailing through the legislature in 17 days, the measure sparked a fierce fight among Senate Republicans over looming federal air-quality regulations and the impact on the state’s 2,300 coal-industry jobs.

The bill brought together, in an election year, longtime opponents and sparked what may have been one of the state’s most expensive lobbying efforts.

The Democratic governor worked closely with his biggest Republican critic, Senate Minority Leader Josh Penry of Grand Junction, and the natural-gas industry, which has publicly attacked Ritter over new oil-and-gas regulations.