In this Sept. 5, 2012 file photo, Tom Steyer, co-founder of Advance Energy Economy, waves as he walks to the podium to address the Democratic National Convention in Charlotte, N.C. A billionaire investor from San Francisco, Steyer's stock is on the rise with California Democrats after voters approved his Proposition 39, which closes a tax loophole that benefited out-of-state corporations.J. Scott Applewhite/The Associated Press
A San Francisco billionaire has challenged TransCanada boss Russ Girling to a live debate on the controversial Keystone XL oil pipeline.
Tom Steyer, an ardent critic of the project and a major Democratic financier, extended his invitation in an open letter to Mr. Girling on Tuesday.
"I care so much that the truth comes out that I hereby challenge you to a debate on the merits and faults of the Keystone XL pipeline," Mr. Steyer wrote.
"Let's have a real, substantial conversation about the issues at hand, and have the viewing public and have the public decide for themselves as to which of us is in possession of the more persuasive and the more important argument."
Earlier this year, Mr. Steyer teamed up with a coalition of environmental groups on an anti-pipeline social media campaign.
A TransCanada spokesman didn't say if Mr. Girling would accept the challenge.
"We respect the environmental review process put in place by the U.S. Department of State and we have been working within that process for nearly five years," said Shawn Howard in an email.
"A decision on a Presidential Permit for Keystone XL will ultimately be made by the administration and we are hopeful that decision is made in the coming months."
Mr. Howard added the project is expected to create thousands of jobs and displace U.S. imports of crude from unfriendly countries — assertions Mr. Steyer disputes in his letter.
A draft State Department report earlier this year raised no major environmental red flags with the proposal, which had been rerouted to reduce some of the ecological impact in Nebraska.
U.S. President Barack Obama — who has final say over the pipeline — has expressed skepticism that the pipeline will be a significant job creator.