The Big Six energy suppliers were targeted by protestors from the Fuel Poverty Action Group over the weekend, who were seeking to highlight the extent of the problem of high bills in the UK.
As well as at offices of providers, town halls where councils were claimed to be not doing enough to support vulnerable residents also saw demonstrations take place, the Independent reports.
Spokeswoman for the group Elizabeth Ziga said: "We want to challenge the Big Six energy companies which control 99 per cent of the energy industry and make record profits off our rising bills."
She added the government has done nothing to deal with the problem of fuel poverty and may have made the problem worse by cutting the winter fuel allowance.
One group of demonstrators managed to get into the head offices of British Gas, where they had an exchange with chief executive of the firm Phil Bentley.
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