Updated

After a week of intense scrutiny and questions of integrity, Green Jobs “czar” Van Jones has resigned his position, effective immediately.

Jones sent a letter to the chair of the Council on Environmental Quality Nancy Sutley. “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,” the written statement says. It goes on to say, “ 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.”

Reports about Jones and some controversial remarks began surfacing early in the week when a video of the best-selling author appeared showing him calling Republicans “a**holes”. But that was only the tip of the iceberg for Jones and his detractors. Shortly after the video came to light, there was another discovery. In 2004, Jones signed a petition implicating the Bush administration in the terror attacks on September 11. For his part, Jones said he didn’t know what he was signing at the time, but the admission only added fuel to the fire and calls for his resignation have been growing. On Thursday, Jones released a statement about the petition and the statements made prior to his job in the administration. "In recent days some in the news media have reported on past statements I made before I joined the administration - some of which were made years ago. If I have offended anyone with statements I made in the past, I apologize,” Jones said. “As for the petition that was circulated today, I do not agree with this statement and it certainly does not reflect my views now or ever.”

As recently as Friday the administration continued to support Jones. Press Secretary Robert Gibbs told reporters while the petition is “not something the President agrees with,” he said Jones continued to work in the administration.

But that backing did little to deter lawmakers on Capitol Hill. Rep. Mike Pence (R-IN) became the first lawmaker to call on Jones to resign, issuing a press release calling for a moratorium on the hiring of additional "czars" until the vetting process in Jones's case could be properly investigated. Senator Kit Bond (R-MO) demanded that the Senate Green Jobs and New Economy Subcommittee conduct hearings to probe Jones's behavior and "reassure the American people that their government is safe from his divisive, incendiary and ultimately counterproductive sentiments."

The Obama administration has not commented on the resignation, but CEQ chair Nancy Sutley issued a statement shortly after Jones resigned. "I have accepted the resignation of Van Jones and would like to thank him for his valuable contributions to the Council on Environmental Quality. Over the last six months he has been a strong voice for creating 21st century jobs that improve energy efficiency and utilize renewable resources. We appreciate his hard work and wish him the best moving forward."

***Fox News Correspondent James Rosen contributed to this story