An Avro customer in a household using a typical amount of gas and electricity, who got a fixed rate deal in August, would have been paying £1,087 a year, according to price comparison site Uswitch. In March, they could have got a deal costing £920 a year.

The Petrol Retailers Association (PRA), which represents petrol station operators across the UK, said that some sites across the UK were seeing delivery delays, but that they were largely confined to London and the South-East, and were 'temporary by nature'.

"However, it is important that consumers contact Trading Standards via the Citizens Advice Consumer Helpline if they are concerned about misleading green claims, so that these claims can be investigated and the appropriate action taken, whether that be advising the...