Question to the Department for Business, Energy and Industrial Strategy:

To ask the Secretary of State for Business, Energy and Industrial Strategy, which energy company is the largest dual fuel supplier in each electricity supply region; and what proportion of dual fuel customers are with that supplier in each such region.

The Department collects data on the number of customers on dual fuel tariffs from energy suppliers in confidence. The Department is therefore unable to publish any comparisons between companies or data on the proportion of dual fuel customers for each supplier in each region.