Up to 1,600 jobs are to be lost at 12 nuclear power sites by September next year, including one at Harwell.

Energy company Magnox has already shut down 11 of its plants and the only one in operation — Wylfa, on Anglesey, in North Wales — is due to stop generating power at the end of this year.

The company said decommissioning the sites was “always going to lead to a reduction in staffing levels”.