[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/09/03/art.sanford.0903.gi.jpg
caption="The South Carolina Republican Party voted to censure Sanford in July."](CNN) - Just hours after Gov. Mark Sanford held a news conference Thursday to fight back against Republican legislators seeking his ouster, the South Carolina Republican Party dealt him another blow by formally calling for his resignation.
Two-thirds of the GOP's executive committee voted to call for the governor's resignation at the end of an hour-long conference call organized by state Republican Party Chairwoman Karen Floyd.
Floyd sent a letter to Sanford after the result was announced informing him of the vote.
It is a stinging rebuke for Sanford from the grassroots wing of the party that has long been his base of support. Members of the party's executive committee are volunteers elected by their fellow political activists - the kind of Republicans who make phone calls, stuff envelopes and knock on doors during election years.
While Sanford has sparred publicly over his two terms with state GOP lawmakers, who have also called for his resignation, the state's grassroots activists have been dependably in his corner.
The vote was also a formal change of course for the state party: Floyd convened a similar conference call in July after Sanford revealed his extramarital affair, which resulted in a vote to censure Sanford for "repeated failures to act in accordance" with the party's core principles and beliefs. But at the time, the party did not ask for the governor to step down.
Sanford's spokesman Ben Fox immediately released a statement following the vote insisting "that working South Carolinians are ready to move beyond this political circus and media-driven distraction." He thanked the committee members who voted against the measure.
"We'd also thank those on the committee and others across the state who've cautioned against a rush to political judgment that would ultimately overturn an election before all the facts and indeed the 'rest of the story' is laid out," Fox said.