WASHINGTON (Reuters) - Republican presidential contender Jon Huntsman's campaign manager Susie Wiles, resigned Thursday and will be replaced by communications director Matt David, a campaign official said.
Senior Huntsman adviser John Weaver did not explain the departure of Wiles but said it represented a move into "phase two" of Huntsman's 2012 candidacy.
Huntsman, a former Utah governor who left his post as ambassador to China earlier this year, has been lagging in polls since entering the Republican race last month.
"Susie has served the campaign well and was vital in getting it off the ground in such a short time-frame," Weaver said in a statement released by the campaign.
"In just under three months Governor Huntsman has returned from China, launched a campaign and created a strong infrastructure in the 3 early primary states," he said.
"Now the campaign is moving into phase two which will be more aggressive from a messaging and tactical standpoint and Matt is prepared to take that on."
Like Weaver, David is a former aide to Arizona Senator John McCain, who was the 2008 Republican presidential nominee.
(Editing by Eric Beech)