Who is Max Caller CBE - the man appointed to head up Government's Northamptonshire County Council investigation?

Mr Caller has previous experience of a 'best value' inspection when he was named as one of the commissioners hired to look into failings in the conduct and governance of Tower Hamlets council in east London, in a role which lasted more than two years, from December 2014 to March 2017.

The Tower Hamlets inspection was called by previous communities minister Eric Pickles under section 10 of the Local Government Act 1999, the same law exercised this week by Sajid Javid.

The ministry of housing, communities and local government said Mr Caller has extensive experience of leading large local authorities, and particularly in diagnosing poor practice and leading improvement, as well as dealing with complex budgets.

"The Secretary of State has determined that he is the best person for the job,” said a spokesperson for the ministry.

Mr Caller's previous roles in local government include four years as the chief executive of the London Borough of Hackney from 2000-2004.

During his time there he managed the transition of the authority from the worst in the country to one of the fastest improving.

Before that, he was the chief executive of the London Borough of Barnet for 11 years, from 1989 to 2000, where he introduced a cabinet form of governance and a scrutiny system, which was deemed one of the models for subsequent legislation.

He is the former chairman of the Local Government Boundary Commission for England, a role he occupied from April 2010 to December 2015.

Mr Caller has done political work outside of the United Kingdom, overseeing elections in Albania and Montenegro, and as a Commonwealth observer for elections in Kenya and Ghana.