(Reuters) - Republican presidential candidate Michele Bachmann has lost a second top campaign staffer in another setback before the Iowa caucuses next week, NBC News reported Thursday.

Bachmann's political director, Wes Enos, resigned a day after her Iowa campaign chairman, Kent Sorenson, left to support Texas Rep. Ron Paul's bid for the Republican nomination.

Enos resigned after he had publicly defended Sorenson, an Iowa state senator, against charges that he had accepted money from the Paul campaign in violation of state law, NBC reported.

Sorenson denies that any money was offered by the Paul camp or that he accepted money to endorse the Texas congressman.

A spokeswoman for the Bachmann campaign was not immediately available for comment.

In an interview on Fox News, Bachmann said Sorenson had told her and others in her campaign that he had been offered money, a lot of money by the Ron Paul campaign.

This is really about the Ron Paul campaign, she added. They are nervous because their momentum has gotten stalled.

Bachmann won the Iowa straw poll in August but then fell out contention.

(Reporting By JoAnne Allen)