Here is his statement:
"I am resigning my post at the Council on Environmental Quality, effective today," Jones said in a letter of resignation.
"On the eve of historic fights for health care and clean energy, opponents of reform have mounted a vicious smear campaign against me. They are using lies and distortions to distract and divide," he said.
"I have been inundated with calls -- from across the political spectrum -- urging me to 'stay and fight,'" he continued. "But I came here to fight for others, not for myself. I cannot in good conscience ask my colleagues to expend precious time and energy defending or explaining my past. We need all hands on deck, fighting for the future.
"It has been a great honor to serve my country and my President in this capacity. I thank everyone who has offered support and encouragement. I am proud to have been able to make a contribution to the clean energy future. I will continue to do so, in the months and years ahead."