Why are energy bosses being questioned?
29 October 2013 Last updated at 11:21 GMT
Top executives from the 'big six' energy companies are answering MPs questions on Tuesday afternoon following recent price rises of an average of 9.1%.
Most of the energy firms have insisted the increases are mainly down to higher wholesale prices - but the regulator Ofgem says those prices have risen by just 1.7% over the past year.
So why the discrepancy? BBC business reporter Stephanie McGovern breaks down the figures.