Martin Lewis issued "total no-brainer" advice to billpayers following the announcement on Friday (22 November) that the energy price cap will rise in January.
Regulator Ofgem confirmed the 1.2 per cent increase to its cap would see the typical bill for a household in England, Scotland and Wales increasing from £1,717 to £1,738-a-year, or by around £1.75 a month.
It comes as millions of pensioners face a winter with less support after Labour decided to scrap winter fuel payments for those who do not receive pension credit or other benefits.
The MoneySavingExpert founder told Good Morning Britain viewers they should consider choosing a fixed deal on their energy tariff.