Cain's Chief of Staff Under Fire

Herman Cain's Chief of Staff Mark Block came under fire in a series of testy exchanges with advisors from rival Republican contenders in Washington Tuesday morning. It happened during a panel discussion on the 2012 election hosted by the National Journal.

Block was immediately put on the defensive over the sexual harassment claims which are now threatening to derail the Cain campaign, but he continually repeated the same message.

"Mister Cain, has never sexually harassed anybody, period end of story," Block said. "If we have to spend every hour of every day responding to this ridiculous story it will take us off our campaign. Let's move on, let's talk about what the American people want to hear about and that's jobs, jobs, jobs."

The sexual harassment allegations stem from a Politico report that two women, who were subordinate to Cain while he was CEO of the National Restaurant Association, accused him of inappropriate behavior and reportedly received five-figure payouts after signing an agreement with the trade association.

While Block's response was consistent Tuesday, Cain's version of the story has changed several times. The GOP hopeful first denied knowing of any cash settlements made with his accusers, saying "I hope they didn't get much ‘cause I didn't do anything."

But Cain has reversed himself, revealing details of what he says are part of the sexual harassment claims leveled against him and admitting he was aware of at least one cash settlement. Cain told Fox's Greta Van Susteren it was equivalent to "maybe three months salary."

The Cain team is now also facing allegations it broke election finance laws by taking tens of thousands of dollars from a tax-exempt charity to get the campaign up and running. The charity, Prosperity USA, was founded by Block and is now apparently defunct.

Pressed Tuesday morning on the allegations, Block repeatedly stated, "I can tell you that we have retained an independent outside counsel to look at the story and report back to us."

Other Republican campaigns want answers now. John Brabender, a Senior Strategist for former Sen. Rick Santorum offered Block some advice. "What I would encourage the Cain people to do is help all Republicans by making sure your campaign is forthcoming."

Block however remained defiant. "One of the problems you all have is we have run a non-conventional campaign," he said. "If we're running our campaign in such a horrible way, why do we keep rising in polls. We had one of our best fundraising days ever yesterday, a quarter million in on-line donations."