The energy firm, one of the UK’s smallest suppliers, has said the price hike is necessary due to ‘increasing energy market costs beyond our control, namely the costs associated with buying energy and getting it into customers’ homes, we find ourselves in the position of having to now pass these costs on to our customers.’

Over the past week, both British Gas and SSE have announced prices hikes of 9.2% and 8.2% respectively.

Mark Todd, director of independent price comparison service energyhelpline, said: “Whilst any price rise is not good news, Co-op’s at around half the size of SSE’s and British Gas’s seems much fairer. It will also be implemented after Christmas, in the New Year meaning Co-op customers can have a more peaceful Christmas.

“At 4.5% it is the lowest increase so far, and we urge other suppliers to follow Co-op’s lead rather than that of SSE and British Gas. For Co-op customers the rise will add £57 a year on to an annual bill.

“We are on a countdown of a matter of days before the current cheapest fixed tariffs are pulled. Over thirty thousand people have already come to us for comparisons in a bid to beat the battle of rising prices. However, these are the tip of the iceberg. By the end of the price rises about twenty million households will have been hit if they don’t take action.”