POWER bills for millions of Scots are to soar by another pounds 131 a year.

ScottishPower revealed gas prices will rocket by an average of 17 per cent and electricity by 10 per cent.

The combined average increase is the THIRD by the power company in just NINE months and piles on the misery for hard-up customers.

It will take effect on July 10. The news comes days after it was revealed ScottishPower had forked out pounds 24million in pay-offs to fat-cat bosses.

The firm had warned last month that bills would rise again - despite reporting massive pre-tax profits of pounds 675million.

Energy watch Scotland said the crippling increases would cost the average Scots family an extra pounds 131 a year, with their combined gas and electricity bill rising from pounds 892 to pounds 1023.

Individual increases will depend on the amount of gas and electricity a customer uses and what part of the UK they live in.

The watchdog's Graham Kerr said: "This is the latest blow in a brutal assault on energy consumers.

"Scottish Power customers will find it hard to understand why a company that has just posted record profits needs to raise prices on such a huge scale.

"Scottish Power will be the second most expensive energy supplier in Scotland. Only Scottish Gas will remain less competitively priced."

The firm's 5.25 million customers will receive letters next week detailing their new tariffs.

Staff were briefed on the increases earlier this week.

One employee told the Record: "We don't know how they think they can get away with it.

"The staff were stunned when they were told what they were planning.

"They have already hiked up charges by huge percentages and now they are planning on doing it again.

"Something needs to be done about it."

Scottish Power last night confirmed the price rises, blaming an 80 per cent increase in wholesale energy costs.

The company are planning to offer consumers the opportunity to cap their prices until September 2008 - to protect against further increases in the meantime.

But they will charge pounds 4.20 per month - more than pounds 50 per year - for the privilege.

In March, Scottish Power increased their electricity prices by eight per cent and gas by 15 per cent.

And last October, gas bills rose by 12 per cent and electricity by between five and eight per cent.

Yet the firm's former chief executive Ian Russell, who was sacked in January, received a pounds 4.5million pay-off and a further pounds 6.8million for his pension. Three other axed directors also received bumper payouts branded "obscene" by politiciansand consumer watchdogs.

Scottish Power produce most of the electricity they supply through their own power stations but have to buy most of their gas from other firms.

If they buy at the wrong time or the wrong price, they can end up paying more than their rivals.

Willie MacDiarmid, Scottish Power's director of energy retail, said: "As we indicated last month, wholesale energy costs continue to rise and are now a record 80 per cent higher than last year.

"We now need to pass on some of these increased wholesale costs".

Rival firm Scottish and Southern Energy have pledged not to increase prices until next year.

Combined Scottish Power electricity and gas bills for the average customer after each price rise since March 2004.