Britain has been gripped for a fortnight by revelations about MPs’ use of parliamentary allowances. But, this week, the real world interrupted the stream of outbursts, apologies, confessions and crocodile tears. Standard & Poor’s moved the UK’s credit outlook from stable to negative. This, even more than the expenses drama, is an indictment of British politics.

S&P’s verdict is dramatic but, in truth, nothing has changed. The ratings agency is simply another voice in the swelling chorus crying out for a more credible recovery plan; the analysis contained no information that conscientious investors would not already have been eyeing suspiciously. The International Monetary Fund made a similar case earlier in the week.