The outgoing chairman of British Gas parent Centrica has called for an end to the "Punch and Judy" debate over rising energy bills amid public and political anger at the "big six" providers.

In an article for The Sunday Telegraph, Sir Roger Carr sets out a robust defence of the industry and said investor confidence was being damaged by "political rhetoric".

Figures in an analyst note from Liberum Capital reveal the extent of the damage from the recent reputational blows suffered by the sector, with an estimated £7 billion to £11 billion wiped off from the value of energy stocks in the last two months.

Sir Roger, who is taking over as chairman of BAE Systems in the new year, wrote: "Political rhetoric [has] inflamed consumer passion, fed suspicion, discouraged investment and damaged investor confidence."

He added: "All energy companies have been accused of profiteering, collaborating with competitors, manipulating costs to disguise profits, and caring little for their customers.

"These charges are false."

Any attempt to cap prices would threaten the "financial fabric" of energy companies, according to Sir Roger.

"They have short-term voter attraction, but lay a pathway to long-term under-investment," he said.

E.ON last week became the last of the major providers to raise prices, upping tariffs by an average of 3.7% from January 18.

It said it had scaled back a potentially higher price rise after the Government's change to green levies on energy bills.

British Gas said it would reduce bills by an average of 3.2% on January 1 following the Autumn Statement announcement, which comes after it hit nearly eight million customers with a 9.2% average increase last month.

Sir Roger said the decision to hike prices is not made lightly.

"No energy company wants to increase bills - it enrages customers and damages relationships," he wrote.

Centrica warned last month that it would fail to meet the City's expectations for annual profits after being affected by challenging conditions in its business supply arm across the UK and United States.

But it admitted profit margins in its British Gas residential business would largely hold firm, edging only slightly lower to just under 5%.