Utility firm’s payment criticised by Defra and campaign groups, with some urging Andy Burnham to nationalise it

Thames Water has paid its finance chief a £1m signing fee despite teetering on the brink of a government-handled administration – a decision the environment department labelled “unacceptable”.

The utility company revealed that it made the payment last month, in a letter sent last week by Adrian Montague, its chair, to MPs on the environment, food and rural affairs select committee.