Rep. Mike Castle (R-Del.) is out with an ad attacking his primary opponent, conservative commentator Christine O'Donnell, a week out from the state's Republican primary.

The 30-second spot focuses on issues surrounding O'Donnell's finances, which have made headlines over the past week as national attention has focused on the GOP contest.

The ad claims O'Donnell "didn't pay thousands in income taxes, had to be sued by a university for thousands in unpaid bills" and "defaulted on her mortgage." The ad also references a New York Times story from the end of last week that featured former O'Donnell aides accusing the candidate of not paying her vendors and staff. 


Castle appears determined to not make the same mistake Sen. Lisa Murkowski (R-Alaska) did ahead of her Republican primary with Joe Miller. Murkowski has been roundly criticized for not taking Miller seriously enough and not using her cash advantage to hit Miller with TV ads.  

The Tea Party Express, meanwhile, remains fully committed to the O'Donnell effort, holding a news conference in Wilmington Tuesday morning to outline its final push ahead of the primary.

Spokesman Levi Russell said the group is on track to spend at least $250,000 on TV and radio ads and announced plans for a last-minute direct mail campaign. Anti-Castle mailers are expected to hit mailboxes just before the September 14 primary. 

"Castle is terrified to engage [O'Donnell] on the issues because of his own liberal record," Russell said. "We're going to be doing everything we can to highlight that."

The Tea Party Express also has a rally planned for Wednesday and is launching a "home phone bank" effort for O'Donnell employing it's membership across the country to make calls on her behalf.