Credit rating warning: George Osborne v Ed Balls
A warning light is flashing. The UK's triple A rating is under threat. The chancellor accepted this morning that "Britain's economic reputation is on the line".
Economically, that means Britain could face not just low growth and rising unemployment but, if the credit ratings agencies do eventually downgrade Britain, higher interest rates too.
Politically, it is another sign - following the revelation last year that the government is way off course to meet its borrowing targets - that George Osborne is currently failing in his own terms - ie: in his efforts to cut the debt and the deficit ahead of all other economic goals.
Yet this morning - as I listened from afar on a half-term break - I couldn't help noticing that this latest news simply led both Messrs Osborne and Balls to say "I told you so".
The chancellor says "I told you how serious our debt problem was" whilst the shadow chancellor tells you "I told you the government was making things worse".
It will be Mr Balls, though, who will feel with some confidence that the arguments are moving his way.
Update 1.20pm: The detail of what Moody's are saying is only just reaching me in the middle of nowhere on my half term break.
What Moody's point out, and the chancellor's people have seized upon, is that a downgrade could follow any "reduced political commitment to fiscal consolidation, including discretionary fiscal loosening".
That, says the chancellor, is why Ed Balls' mantra - spend more now to premote growth - isn't borne out by today's report. Mr Osborne's message remains clear - steady as she goes.