A consumer rights group has urged energy suppliers to make pre-payment meters cheaper and more easy to use.
The warning comes from Consumer Focus after it found that around 1.4 million pre-payment users, mostly from vulnerable households, have chosen to go without energy at least once in the past year in order to save costs.
The organisation's estimates are based on 5,726 interviews, 764 of which were with pre-payment meter users.
Half of all households that effectively disconnected their energy supply last year included someone with an illness or disability, while two in five housed children under the age of 16.
Mike O'Connor, chief executive of Consumer Focus, expressed his concern that hundreds of thousands of vulnerable consumers are "walking a tightrope between topping up their energy to stay warm or buying a decent meal" and called for energy suppliers to take urgent action.
"Energy firms could transform the experience of customers by bringing pre-payment meters into the 21st century, making it easier to top up and avoid being cut off," he said.
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