By Suzanne Goldenberg

The Coen brothers have applied their slightly off-kilter sensibility to the campaign against America's coal industry, with a new television advertisement debunking the notion of clean coal.

The filmmaking brothers, working from a concept and script supplied by the ad makers for the environmental campaigners, the Reality Coalition, Reality Coalition environmental campaign, produced a spot showing a salesman spraying black smog from an aerosol can around a home.

"Is regular clean enough for your family?," says the salesman as the children choke and sputter behind him. "Get clean coal clean."

The recruitment of Joel and Ethan Coen marks an escalation of the battle over coal. The final showdown could come as early as this April, with Barack Obama pressing Congress to pass green energy legislation.

Unlike their breakout film Fargo, which showed a corpse being put through a wood chipper, and last year's No Country for Old Men, which had a psychotic killer go after a slew of victims with a pressure-driven device normally used to kill cattle, coal industry executives do not come to a violent end.

The brothers are to produce another television ad for the campaign later this year.

The Reality Coalition, an offshoot of Al Gore's Alliance for Climate Protection, began focusing on industry claims that clean coal was feasible late last year, with high profile advertising campaign.

The anti-coal campaign has been taken up by other organisations, which have taken out ads on bus stops and metro stations against coal.

Reality's earlier television ad showed a man in a hard hat opening the door to a clean coal facility – which turned out to be an empty patch of desert (see below).

The coal industry has fought back just as hard – if not harder. The industry spent about $40m last year on television advertisements and lobbying efforts to prop up the idea that it was feasible to produce environmentally friendly coal.

The Reality Coaltion said yesterday it was prepared to match those outputs as the battle heats up. "We are spending on the magnitude of the coal industry," said Brian Hardwick, the manager of the Reality coaltion.

Some 10,000 young people are set to descend on Washington at the weekend to demand that America reduce its dependence on coal. The event is designed to put pressure on Congress as it drafts new energy legislation this spring.

Hardwick argues that the coal industry has spent more on promoting the notion of clean coal technology than on actual research and development. "The fact is that they don't put their money where their mouth is," he said.