From Today's Times:
Standard & Poor’s (S&P), one of the world’s two main ratings organisation, reaffirmed that its credit rating for Britain’s government debt remained at so-called “triple A” status, a gold-plated standard that is the highest available. But S&P fired a warning shot at the Treasury when it revised its outlook on this assessment from “stable” to “negative”.
The downgrade is in the post. When Darling and Brown cranks up the deficit, the UK's credit rating will slide.