(Adds comment from environmental group)
By Rod Nickel
WINNIPEG, Manitoba, Aug 1 (Reuters) - Three Canadian oil producing companies took out joint full-page newspaper advertisements on Thursday to turn up the pressure on politicians to support the struggling industry ahead of an election in October.
Opposition from environmental and indigenous groups have stalled new pipeline projects in Canada and the United States that are needed to move Canadian crude to refineries. Congested pipelines forced the main oil-producing province of Alberta to curtail production this year to support prices.
Senior executives of Canadian Natural Resources Ltd CNQ.TO , the country's biggest oil and gas producer, Cenovus Energy Inc CVE.TO and MEG Energy Corp MEG.TO signed a letter to Canadians pointing to a 30% reduction in emission intensity from the oil sands during the past 20 years.
"We are asking you to join us in urging Canada's leaders of all political stripes to help our country thrive by supporting an innovative energy industry," the letter, which appeared in several Canadian newspapers on Thursday, read. It said that limiting Canada's oil industry could result in greater use of more highly polluting fuels from other countries.
Alberta's oil sands have been a focal point for global efforts to stifle fossil fuel production by environmental groups who say activity there takes an especially large toll on the environment.
"We are a part of the (climate change) solution, the global solution," MEG Chief Executive Derek Evans told Reuters. "The fact this is prime barbecue and picnic time for politicians, (the ads) encourage Canadians to get out there and talk about the role Canada could play in solving the global greenhouse emissions issue."
The letter did not go into specifics, but the oil industry opposes laws imposed by Prime Minister Justin Trudeau's Liberals that ban oil tankers in northern British Columbia and alter the regulatory process for resource projects.
Environmental groups took issue with the ad's message.
"This is a time where Canadians really need to be calling out their politicians to step up our game on climate, not to be further supporting an industry that harms us," said Anna Johnston, a lawyer with West Coast Environmental Law.
Polls show the Liberals and Conservatives in a close race ahead of the October election.
Canadians' views on the oil industry vary widely by region, ranging from staunch support in Alberta and Saskatchewan provinces that are home to the world's third-largest crude reserves, to stiff opposition in Quebec.
The previous New Democratic Party government in Alberta, which tried to convince Canadians of the merits of expanding the Trans Mountain oil pipeline, was defeated this spring.