Around 500,000 low energy users, who tend to be on the lowest incomes, could be advised on the wrong tariffs, under new proposals by Ofgem, Which? said.
Rising energy bills remain one of consumers' top financial concerns yet six in 10 of us have never switched supplier as people are left baffled by the vast array of complicated tariffs.
These current proposals are far too complicated and will fail to achieve their aim of making it easier for people to find the best deal, with three-quarters of people being asked to compare prices that are not based on their energy usage.
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Marjorie and Michael Cawdery, both 83, are understood to have been stabbed to death in a killing their family called "incomprehensible".
Detectives have launched a murder investigation following the shooting in Brent, north west London on Friday night.
Hot and humid throughout the Bank Holiday Weekend.