Shares have plunged by more than a fifth since last autumn when Labour leader Ed Miliband pledged to freeze tariffs if the party wins power, and were driven down further following a fresh intervention this month by Energy Secretary Ed Davey.
BAE Systems also reports annual profits on Thursday, following a year in which it has shed hundreds of UK jobs and faced a major setback in its Typhoon jet programme.
The group announced in November that it would stop shipbuilding in Portsmouth with the loss of 940 jobs, while there would be 835 redundancies in Glasgow, Rosyth, Fife, and at Filton, near Bristol.
Experts at Deutsche Bank are expecting group sales to have increased by 5.5% to £18.8 billion over 2013 and are pencilling in a 9% rise in underlying pre-tax profits to £1.8bn.
Supermarket giant Asda will give its belated sales figures for Christmas trading on Thursday when US parent Wal-Mart reports its full-year results.
The Leeds-based group has narrowly retained its place as the second largest in supermarket operator in the UK in spite of pressure from Sainsbury's.
Newcastle United owner and Rangers investor Mike Ashley sees his retail empire Sports Direct International posts third-quarter figures on Wednesday, having recently said trading had returned to normal levels.