The private gas companies were nationalised in the 1940's under the Atlee Government until the Thatcher Government privatised British Gas in the 1990's and there is now growing calls for renationalisation again.
Just been listening to an interesting programme;
https://www.bbc.co.uk/programmes/m001j3lj
What happens when a Government nationalises a company? Will I get the FTSE valuation of my shares on the date of nationalisation, or what the Government decides to pay it's owners?