Barack Obama's vice presidential selection team has begun to ask potential candidates for information and documents, a signal that the formal vetting phase of the search process has begun.

Last week, members of the team gave Sen. James Webb of VA a list of what they needed to begin their investigation of his background and career. Webb refused, telling them that he did not want to be considered for the position.

In a statement today, Webb disclosed that he had "communicated to Senator Obama and his presidential campaign my firm intention to remain in the United States Senate, where I believe I am best equipped to serve the people of Virginia and this country. Under no circumstances will I be a candidate for Vice President."

A Democrat close to Webb confirms that a request for documents preceded his declaration to the Obama campaign. The Democrat said that Webb did not want to relive the vigors of a campaign so soon after his election to the Senate.

Webb's statement suggests that Caroline Kennedy and Eric Holder, the two leaders of the team, had received instructions from Sen. Obama to vet a number of finalists, including Webb.

In general, candidates who are asked to provide information ranging from references to tax returns have been promoted to the next round by the nominee himself. Because the vetting takes lots of time, nominees tend to ask for vets of only those under serious consideration.

Republicans close to the McCain campaign say that veepstakes supervisor A.B. Culvahouse has begun to vet between eight and ten candidates, including Gov. Tim Pawlenty of MN and Ex-Gov. Mitt Romney of MA.

An Obama spokesman did not respond to an e-mail seeking confirmation or comment.

In 2004, one potential vice presidential candidate, Gov. Bill Richardson of New Mexico, took himself out of John Kerry's search process right just as his formal vetting began. Richardson and Johnson have differed in their accounts of how far along Mr. Richardson was before he decided to publicly declare that he would not be on the ticket.

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