An environmental group is calling on President Obama’s campaign to take down a TV ad criticizing Republican challenger Mitt Romney for declaring years ago that a Massachusetts coal-fired power plant “kills people.”

Republican presidential candidate and former Massachusetts governor Mitt Romney greets coal miners in August during a campaign rally at American Energy Corporation in Beallsville, Ohio. (Justin Sullivan/Getty Images)

The spot says nothing directly about Obama’s own stance on the fossil fuel. But the mere suggestion that Obama would be a better friend to coal than Romney was enough to upset environmentalists.

“This ad is the height of political cynicism,” said Brad Johnson, campaign manager for Forecast the Facts, which has been pushing to make climate change an issue in the presidential race. “Voters in Ohio and Virginia are already suffering the ravages of coal pollution, from dirty lungs to poisoned weather. President Obama should be ending his silence on climate change, not perpetuating the myth that burning coal has a viable place on a livable planet by criticizing Romney’s since-recanted moment of truth about dirty coal.”

The group has created an online petition asking Obama to yank the commercial: “Tell the Obama campaign: stop your cynical pro-coal ad,” it reads.

Coal has emerged as an important issue in the presidential race, with Romney contending that Obama’s environmental policies have been hostile to it and other fossil fuels — at a steep price to jobs and energy independence. Obama has insisted that he supports “clean coal” operations as well as renewable sources of energy.

Obama’s ad, launched late last month, was meant to counter Romney commercials asserting that the president has been waging a “war on coal.”

“Seen these new ads where Mitt Romney says he’s a friend of coal country?” Obama’s ad begins. “This is the guy who wants to keep tax breaks for companies that ship American jobs overseas. The same guy who had a Swiss bank account and millions in tax havens like Bermuda and the Caymans. And on coal? Well, here’s what he said as governor outside a coal-fired power plant: ‘I will not create jobs or hold jobs that kill people. And that plant, that plant kills people.’”

Asked to respond to calls to pull the ad, Obama spokeswoman Joanne Peters said this via e-mail:

“Mitt Romney once again is trying to hide his true positions from Virginians, this time by trying to reinvent his stance on coal. The truth is, while he now claims he supports coal, Mitt Romney has been a longtime critic of coal-fired power plants, and once declared that they ‘kill people.’ Mitt Romney has made it very clear that he will say anything to win, even if it’s not true, and this ad seeks to tell Virginians what Romney’s true record is.”

Curt Cashour, a Romney spokesman, had this to say:

“The fact that President Obama’s own die-hard supporters don’t believe him when he says he supports coal underscores how laughable the claims in his ads are. President Obama has mounted an all-out war on coal that is killing jobs in Virginia and no amount of disingenuous advertising can change that fact. There is only one candidate in this race who will stop President Obama’s attacks on coal miners, their families and the coal industry as a whole, and that’s Mitt Romney.”