Fuel poverty activists slated Scottish Power's bosses yesterday as they became the latest board to blanche over Labour's proposed tariff cap.

The firm's chief corporate officer Keith Anderson invoked shareholders' "doubts and fears" in an open letter to Labour leader Ed Miliband urging him to abandon the pledge.

The would-be PM has promised a price freeze on all gas and electricity bills until 2017 if Labour wins the next election - a move that would save the average household around £120 a year on current projections.