MORE than one milllion householders in Scotland are braced for another hike in electricity and gas prices as one of the "big six" energy firms looks ready to announce a further price rise ahead of winter.

Centrica-owned British Gas – and its subsidiary Scottish Gas – are poised to announce that tariffs are to rise in high single percentage digits, reports have claimed.

The average British Gas annual dual-fuel bill for gas and electricity currently stands at £1260, meaning a 5% increase would add £63, while an 8% rise would put on £100.

A British Gas spokesman said: "We do not comment on future pricing movements.

"We do not comment on speculation about future pricing movements."

British Gas put gas and electricity tariffs up by 18% and 16% respectively in August 2011, blaming higher wholesale costs, but this was followed by a drop of 5% in electricity tariffs in January when prices eased.

The supplier is expected to say it was forced into the latest increase by higher wholesale prices and the rising cost of using the National Grid network.

The energy giant, which has 15.9 million customers across the UK, warned in May that its costs were rising, with the price of supplying the average household this year going up by £50 due to wholesale prices.

British Gas also said that it was battling with higher costs for transport and distribution.

The rise comes despite the firm announcing a 23% leap in profits, admitting last year's hefty price rises helped it pull in a total of £345 million in operating profits in the first half of the year.

Caroline Flint, Labour's Shadow Energy and Climate Change Secretary, said: "Unless ministers get to grips with spiralling energy bills, people will rightly think that this Government is completely out of touch with families and pensioners struggling to make ends meet."

The reported rise comes as rival SSE prepares to increase tariffs by 9% on average on Monday.

This will hit about five million electricity customers and 3.4 million gas customers.

Other big suppliers – such as EDF, ScottishPower and nPower – are not expected to follow suit and announce higher prices, with E.ON the only supplier to guarantee a price freeze in 2012.

Meanwhile, the UK Coalition Government has announced plans to work with the Scottish Government to speed up the progress of renewable projects on Scottish islands and £20 million of investment into new carbon capture technology.