It has launched a press advertising campaign giving consumers advice on how to control and reduce their energy bills in light of the changes.
In retaliation, rival provider EDF Energy has launched a press advertising campaign inviting consumers to “relax” and fix their energy prices until September 2012 by switching to its services.
British Gas, the Centrica owned firm, announced last week that it will raise its gas prices by 18% and electricity prices by 16% from 18 August.
It cites rising wholesale prices and increased dependency on overseas gas supplies for the price rise.
All six major energy companies, except Scottish & Southern, have raised their prices this year. Scottish Power will raise its gas prices by 19% and electricity by 10% from August.
Npower increased its pries 5.1% in January, E.on raised gas by 3% and electricity by 9% in February and EDF raised its gas prices 6.5% and electricity 7.5% in March.
Energy secretary Chris Huhne has dismissed claims that the UK’s energy prices are higher than the rest of Europe and urges consumers to use price-comparison sites to save money.
He added that the UK must reduce its dependence on oil and gas and increase the use of renewable and low carbon energy to stop price fluctuations.
Ofgem, the energy sector regulator, said earlier this month that it would investigate the discrepancy in wholesale prices paid by the big six energy providers.