Pressure is being brought on the UK government’s energy secretary to introduce a price cap on domestic heating oil.
The plea to Kwasi Kwarteng comes after prices more than doubled in a fortnight.
Currently, consumers heating their homes using gas or electricity have some protection from price rises under Ofgem’s energy price cap.
However, there is no financial protection in place for the 1.5 million households that rely on heating oil.
The price per litre of heating oil has surged from 66.74 pence on 24th February to 148.25 pence on 9th March – a 122 per cent increase in a fortnight.
In total, around 4 million UK households are not connected to the gas grid, with 1.5 million of those homes relying on heating oil.
Isles representatives Alistair Carmichael MP and Beatrice Wishart MSP have joined a Liberal Democrat campaign demanding the cap be introduced.
Orkney MSP Liam McArthur is also taking part in the campaign.
The MSPs have also written to Scottish energy and transport secretary Michael Matheson, calling for Scottish government support.
Mr Carmichael said: “We already have some of the worst rates of fuel poverty in the country so the absence of this cap is hardly helping matters – even if we have seen the limitations of the price cap itself in recent months.
“Ultimately this is a question of equality of treatment. If it was hard to justify the absence of a price cap for off-grid households before the current crisis, it is unfathomable now.
“If the business secretary cannot agree to a price cap for off-grid families then he had better offer an alternative solution – and fast.”
Ms Wishart added: “Islanders already count among those most likely to be in extreme fuel poverty.
The UK and Scottish governments need to do all they can to help households and families who are facing estimated costs for a 3-4-bedroom home of around £370 per month.
“We cannot allow the choice between heating and eating to become even more widespread. Off grid households need greater support and a cap on oil would be a great help to many islanders.”