Centrica, the owner of British Gas, has warned of "challenging" trading conditions despite offering its chief executive a 44% pay rise.
Iain Conn is expected to receive a pay package worth £2.4 million for 2018, up from £1.7m in 2017. However, shareholders are understood to be unhappy with it and could block such a move.
Centrica said warmer weather, a cap on standard variable rates and falling gas prices would all affect its financial performance in the first half of its financial year.
The union GMB has called on major shareholders to vote against Mr Conn's pay, highlighting that the company has cut thousands of jobs and its pensions benefits.
In addition, British Gas has continued losing customers in the first few months of the year. The energy supplier lost nearly 750,000 customers last year, and lost a further 234,000 in the first four months of the financial year.