By Paul Lewis
BBC Radio 4's Money Box
A run on the society caused its collapse last November
Politicians in Northern Ireland are asking Gordon Brown to compensate 9,500 people who have lost their savings.
In March the prime minister promised savers protection when any UK financial institution gets into trouble.
But seven months after Presbyterian Mutual Society collapsed, none of its savers has been given back a penny.
The government insists they were not "savers" but "investors" with shares in the society.
Speaking on BBC Radio 4's Money Box, Jeffrey Donaldson MP - who is also a member of the Northern Ireland Legislative Assembly and assists the First Minister Peter Robinson - said he "did not accept" that view.
"We believe a mutual society like Presbyterian Mutual Society is on a par with building societies who have been helped by the government," he said.
"If you are living in Northern Ireland as a British citizen and you hear your prime minister say that all savers will have their money protected and yet a UK financial institution like Presbyterian Mutual can't have savings protected, we think that is unfair."
Jeffrey Donaldson confirmed that the First and Deputy First Ministers are meeting Gordon Brown to discuss the collapse of Presbyterian.
"The object of the meeting is to keep him to his promise that every saver in the UK would get their money back where a financial institution gets into difficulties."
Ian McGimpsey who represents savers in the Presbyterian said great hardship is being caused.
He told the programme: "Some people have sold a business and put their money into the Presbyterian Mutual Society and they haven't got the money to pay their income tax. They are having to borrow it.
"People in care homes - their savings are frozen, they are in terrible difficulties and are so worried."
Jeffrey Donaldson said it was the job of the UK Government, not the devolved Northern Ireland Assembly, to pay compensation.
"Our legal advice is that it is not a devolved matter in relation to government intervention. Although Presbyterian is registered with the Department for Enterprise in Northern Ireland, financial services is not a devolved matter and banking is not a devolved matter," he insisted.
"The Secretary of State [Shaun Woodward] did say in the House of Commons that he was prepared to intervene. We are now waiting to see what that intervention will be."
BBC Radio 4's Money Box was broadcast on Saturday, 13 June at 1204 BST