The reaction of energy companies to Ed Miliband’s pledge to curb price rises tells us all we need to know about the power of these companies.

They have responded with a warning of the lights going out all over the country. But is this a warning or a threat?

Are they threatening us, and any political party which dares to interfere with their method of pricing for the lighting and heating of our homes, to plunge us all into darkness?

Christopher Fox-Walker Meads Road, Eastbourne