Bosses from the Big Six energy firms have been called to give evidence to a committee of MPs about recent hikes in prices.
The Energy and Climate Change Committee said other smaller energy suppliers will also appear before Parliament on October 29.
Sir Robert Smith (Liberal Democrat, West Aberdeenshire and Kincardine), acting chairman of the committee, said: "The committee has today decided to call in the energy bosses in the context of the latest wave of price increases."
Three of the Big Six have announced price rises in recent weeks - 8.2% by SSE, 10.4% for electricity and 8.4% for gas by British Gas, and 9.3% and 11.1% respectively by npower.
The committee said the session will explore a range of issues, including reasons and justification behind recent energy price rises, the difference of pricing policies between energy suppliers, and how the transparency of energy company profits can be improved.