Ms Schild said “Keystone XL is one rare national issue that attracts consistent support across the political spectrum.

“The new ads review the long list of prominent Keystone XL backers from public figures like Warren Buffett, Bill Clinton, and George W Bush, to editorial boards including the Washington Post, Wall Street Journal, and USA Today. Eighty-two per cent of American voters support Keystone XL construction and the support is strong across all political identifications. About 8 in10 Independents and Democrats agree that the pipeline is in our national interest.

“Four out of four State Department assessments have affirmed the project is safe for the environment,” said Ms Schild. “Bipartisan majorities in both chambers of Congress voted to support the approval of the pipeline. There is no question the economic, energy security and national security benefits of Keystone XL serve our national interests. All that remains is for President Obama to heed the overwhelming public support and decisive evidence accumulated over almost five years of study and move forward with Keystone XL.”

The advertising campaign will reach states during the August recess period including New Mexico, Minnesota, Delaware, Pennsylvania, North Carolina, South Dakota, Missouri, and Florida.