Carillion has crashed; it's winter for social care provider Four Seasons. The National Audit Office, using polite accountant speak, has condemned PFI as a giant scam and, implicitly, convicted HM Treasury of gross negligence. For the first time in the 30-year advance of outsourcing in public services, a principal political party is now officially opposed.

So dominant a model for so long, contracting now looks tired, undependable, passé. Problems have been shaping for years. Before Carillion, government ministers had to bail out companies that were supposed to be replacing public with cutting edge private provision – in probation, for example.