Energy firms increased their profits from customers by 50 per cent in the space of four months, while Britain shivered through the coldest winter for decades. In the autumn the firms were making £65 annual profit per customer but that figure is now £97 on a typical household energy bill of £1,200. The energy regulator has the power to refer firms to the Competition Commission and Tim Yeo, Tory MP for Suffolk South, said: "Ofgem need to show some teeth."