Energy bills could more than double to £4,200 a year by January, households have been warned.
The predicted surge is even more than feared after regulator Ofgem this week confirmed its price cap would be reviewed every three months, but also announced further, unexpected changes to the way it is calculated.
Investment bank Investec now thinks the price cap - currently £1,971 a year - will jump to £3,523 in October, then leap to £4,210 in January.
