Activists who oppose oil and natural gas development have launched a new campaign to save a last-minute Obama administration regulation that’s facing repeal in the U.S. Senate.

The Western Leaders Network (WLN) is trying to defend the “venting and flaring” rule, issued by the U.S. Bureau of Land Management (BLM) two months before President Barack Obama left office. The group is led by Mark Pearson, board secretary of the San Juan Citizens Alliance (SJCA), and Gwen Lachelt, a former Earthworks activist who now serves as a commissioner in La Plata County, Colo.

The SJCA has previously admitted using “street fight” tactics to make oil and gas “as difficult as possible to develop,” and Earthworks has said it’s engaged in a “war on fracking.”

The WLN sent a letter to federal lawmakers this week claiming the venting and flaring rule “will cut natural gas waste” and “will put our energy resources to good use.” The letter responds to widespread criticism of the BLM regulation across Colorado and the West. In Colorado, critics include the Grand Junction Chamber of Commerce, Southern Ute Indian Tribe, Colorado Association of Commerce and Industry, Colorado Business Roundtable and Club 20, a coalition of local governments, tribes, businesses and citizens from the Western Slope.

Other opponents include Utah Gov. Gary Herbert (R), New Mexico Gov. Susana Martinez (R), the New Mexico Business Coalition and the Greater North Dakota Chamber. Three states – Wyoming, Montana and North Dakota – have sued to stop the rule and Western lawmakers are also leading an effort to repeal the regulation using the Congressional Review Act (CRA). A CRA disapproval motion, which would effectively repeal the BLM rule, passed the U.S. House last month and is now before the Senate.

“The players behind this new group oppose oil and natural gas development in any way they can,” Christi Zeller, executive director of the pro-industry La Plata Energy Council, told Western Wire in reaction to the launch of WLN. “They don’t support the BLM venting and flaring rule because it will put our energy resources to good use. They support the rule because it will result in less energy production. The talking points don’t match the track record,” Zeller said.

Supporters of the new BLM rule claim it will prevent natural gas from being wasted, increasing production of the fossil fuel and resulting in more royalty revenue for federal state and local governments. But critics of the rule say just the opposite will occur: The extra red tape will block many wells from being drilled and force others to prematurely shut down due to higher costs, resulting in lower oil and gas production and less royalty revenue.

Opponents of the Obama methane regulation argue that the BLM can curb venting and flaring more effectively by approving more pipelines to transport natural gas away from well sites to the markets where it can be sold. But new pipeline projects have been opposed by the Sierra Club, the Center for Biological Diversity and other “keep it in the ground” activist groups – the same groups that have called the venting and flaring rule “a positive step” towards ending fossil-fuel production on public lands completely.

The leaders of WLN also have a history of opposing oil and gas development. In 2010, the SJCA described its campaign against oil and gas development as “a street fight” and “a back-alley fight” with many different tactics. “You’ve got to fight it anyway you can,” an activist with the group told an Earthworks conference. “Whether it’s bans on drilling, whether it’s local regulations, whether it’s severance taxes, you have got to put up as many obstacles, you have to make it as difficult as possible to develop.”

Lachelt, the La Plata County Commissioner, was SJCA’s first executive director and she also spent more than a decade as an Earthworks activist before running for public office in 2012. Under Lachelt’s leadership, Earthworks founded the “Stop the Frack Attack” coalition, which was launched with a 2012 rally against oil and gas development in Washington, D.C. Its members include some of the nation’s largest anti-oil and gas groups, including Sierra Club, Center for Biological Diversity, Food & Water Watch and In 2014, Earthworks said it’s engaged in a “war on fracking.”

Both Lachelt and the SJCA have since tried to distance themselves from anti-oil and gas activism, after their past work on such campaigns became an issue in the 2014 Colorado governor’s race. Gov. John Hickenlooper (D) appointed Lachelt to a special oil and gas task force while she still served on the SJCA board, a move that was strongly criticized by his opponent, former U.S. Rep. Bob Beauprez (R).

The WLN website – launched last month – says the group aims to “unite, support, and cultivate pro-conservation local officials” in the West. The group’s letter to federal lawmakers lists roughly 60 local officials, state legislators and one former council member of the Ute Mountain Ute Tribe as co-signers.

Those names include other local officials with close ties to environmental activist groups, including Boulder County, Colo. Commissioner Elise Jones, a former activist with the League of Conservation Voters and the Colorado Environmental Coalition, and Lafayette, Colo. City Council Member Merrily Mazza, who helped lead a local “ban fracking” campaign in 2013.