Plans would cost billions

ENERGY: Nationalising main power providers could cost £185billion, according to a report by investment banking group Jefferies in 2015.

WATER: Regulator Ofwat puts the industry’s ‘regulatory capital value’ – covering the operations it oversees – at £6 billion.

ROYAL MAIL: Shares currently listed at 330p each – valuing Royal Mail at £3.3billion.

RAIL: The state owns Network Rail, which controls tracks and stations. It could take over passenger services, which are run as franchises, at no cost – but would need to buy engines and carriages, which cost operators £1.4billion in 2015-16, a Commons Library paper shows.

PFI: There were 716 PFI projects in March 2016, with a total value of £5 .4billion. Private firms behind those are due around £220billion in the coming decades.