New figures have exposed the “scandal” that means families in the north and north-east pay more for electricity than anywhere else in Britain.
Official statistics from the UK Government confirm that the area has the highest bills of all 14 regional supply areas across the country.
The annual cost in northern Scotland last year was 7.8% more than the UK average, 10.4% higher than the central belt, and 12.5% more than the cheapest region.
The breakdown triggered fresh claims last night that the market was a “post-code lottery” and should be overhauled.
Welsh nationalists Plaid Cymru obtained the figures using parliamentary questions amid fury that Wales pays the most, after northern Scotland.
“This is a scandal which cannot go on,” Plaid MP Hywel Williams said.
The party called for the creation of a not-for-profit energy company to buy at wholesale prices and sell directly to consumers.
It has also launched a petition to “register people’s anger at the soaring costs”.
Last October, the Press and Journal launched the Fair Deal on Energy Prices campaign after revealing that the surcharge adds about 2p-per-unit of electricity to bills in the north and north-east.
Since then there have been growing calls for the regional system to be abolished and replaced with a flat, national rate.
The energy and climate change select committee at Westminster last week recommended that the UK Government publish an in-depth study into the proposed change.
Scottish Secretary Alistair Carmichael gave his backing to the P&J’s campaign on Wednesday, with the Liberal Democrat MP for Orkney and Shetland calling on the regulator Ofgem to take action.
Kevin Stewart, the SNP MSP for Aberdeen Central, said last night that UK ministers must take responsibility.
“People in the north and north-east of Scotland are being hit in the pocket because of a Westminster energy policy that penalises consumers and electricity producers in our area,” he said.
“The UK Government keep passing the blame on to the regulators when this issue is raised, but there has been failure by successive UK Governments to tackle this inequality, which means larger bills for my constituents and hundreds of thousands of others in Scotland.
“This rip off must stop.”