Moodys - Nationwide: The outlook is Negative

so as a bank its at the second lowest level of the possible rating “modest intrinsic financial strength, potentially requiring some outside support at times” and if it were not for the blanket guarantee its bonds would be not Baa3 ("moderate credit risk. They are considered medium-grade and as such “protective elements may be lacking or may be characteristically unreliable”) but would be below investment grade at Ba2 or Ba3 ("Obligations rated Ba are judged to have “questionable credit quality”) .
Junk in other words.