UNISON has called for a new code of conduct governing private companies that deliver public services, following the collapse of Carillion and profit warnings from Capita.

The union wants firms to abide by a set of principles to ensure the driving force behind services is the public interest, though its preferred option remains in-house provision.

Unison general secretary Dave Prentis has written to Cabinet Office minister David Lidington calling for a new public service ethos to underpin contracts handed to private firms.