The EnergyOnline Extra Saver service is now 6.2 per cent cheaper than British Gas’ standard dual fuel deal, at £54.

But the energy company issued no further details of the other reductions it would “shortly” make when speaking to uSwitch.com.

It will offer varied discounts across the ‘energy regions’ of the UK, giving customers cheaper deals in eight regions with six regions still ‘held’ by British Gas.

In London, Powergen will become the cheapest supplier with a 17 per cent online discount, but in the East Midlands, with only a 7.6 per cent discount, it remains the most expensive large provider.

The regional approach introduces an unprecedented element into the price war, uSwitch commented.

But moneysupermarket.com’s head of utilities, Paul Schofield, suggested that the “strategic decision to target specific regions with significantly higher discounts for its online tariffs” signalled that Powergen “feels unable to compete with British Gas’ price cuts across the board”.

Powergen supplies gas and electricity to nine million UK customers.

To compare gas prices, click here.

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