On behalf of 21,000 members working in generation, distribution and transmission, Prospect deputy general secretary Garry Graham said:

“We are in the incongruous situation that the financial crash and recession probably helped keep the lights on. But energy margins are at an historic low and as the economy recovers, and demand increases, so will the pressures on margins leaving us facing a real risk that the lights may go out.

“It is absurd that as the first industrial nation, we are now paying industry to cease production at certain peak periods. What message does that send to investors?

“Certainly renewables have a role to play but we need a mix of generation to cover us on cold winter days when the wind doesn't blow. The time has come to stop simply talking about and start actually investing in new generating capacity.”