Asked to choose between Moody’s and the mutuals, most people would agree building societies have had the better credit crunch. So it is easy to condemn the rating agency’s decision to downgrade nine building societies as an attempt to overcompensate for well-documented rating failures earlier in the crisis. Too easy.

Moody’s stress-testing of the sector does look extreme. A 40 per cent peak-to-trough collapse in house prices would take the market down well beyond the 18 per cent fall so far registered by Nationwide. Moody’s also considered the effect of a 60 per cent drop. That would put the economy into a dire state similar to that conjured up by the Financial Services Authority when it ran Barclays’ balance sheet through the wringer last month. Yet, as a sector, building societies’ arrears amount to less than 1 per cent of mortgage balances, compared with 2.55 per cent at banks.