The correspondence shows Washington based Canadian diplomats describing recommendations from Environment Canada to clean up the oilsands as "simply nutty," proposing instead to "kill any interpretation" of U.S. energy legislation that would apply to Canadian oilsands "to ensure that the oil keeps a-flowing." The correspondence also shows that Canadian diplomats had contacted officials from the American Petroleum Institute as well as Exxon-Mobil Corp., BP, Chevron Corp., ConocoPhillips, Encana Corp., and Marathon Oil Corp. "to point out the potential implication to their imports from Canada."

"We have proof that the Harper government is aggressively intervening in Europe and the United States to kill clean energy policies in the name of promoting the tar sands. Canada is not just exporting dirty oil anymore - we're also exporting dirty policies." said Graham Saul of Climate Action Network Canada.

"A responsible government would see clean energy policies outside our borders as an opportunity to do better, not as a threat," said Clare Demerse, the Pembina Institute's Associate Director of Climate Change.

"We are calling on the governments of Canada and Alberta to stop all efforts to kill clean energy and climate policy in other countries," said Steven Guilbeault of Équiterre.