TVNewser has obtained copies of two letters the North Carolina Democratic party sent today to the campaigns of Sens. Clinton and Obama. The letters, which you can read here and here, are CBS's latest attempt to get the two candidates to agree to debate on the network. Here's the latest offer:

The debate will be held on Sunday, April 27th, from 8:00 to 9:30 PM immediately following 60 Minutes. The debate will air live, during primetime, on the CBS Network, and will be moderated by CBS News Anchor Katie Couric and Face the Nation host Bob Schieffer.

We are moving ahead on our final site survey. We will let you know the site in the next few days as soon as we finalize it. CBS will work with the NCDP's debate consultant, Jenny Backus, to schedule format and logistics calls for your campaign staff in the near future.

Insiders tell us CBS still has other options if April 27 doesn't work for the candidates.