Thousands of people face losing their savings
The Presbyterian moderator wants church members to appeal to Gordon Brown over the Presbyterian Mutual Society crisis.
Thousands of people face losing their savings after the society was placed into administration in November.
In an open letter read out at services on Sunday, Rev Dr Donald Patton urged Presbyterians to sign a petition urging Gordon Brown to intervene.
Dr Patton said the prime minister's decision to guarantee the banking system had triggered the crisis.
"Well it was the action that he took that triggered this problem for the mutual society which was going along nicely," he said.
"No-one foresaw this problem. It has thrown a lot of people who are constituents of politicians here, who are British citizens, into chaos, caused great anxiety to them and caused great problems."
He called on his church to hold together through "stormy times".
A week ago, PMS administrator Arthur Boyd wrote to 9,500 investors recommending that they accept a proposal which, he said, would mean they get some money back.
This would lead to what Mr Boyd called an "orderly run down" of the business, over time.
If this plan is to go ahead, more than 50% of investors must vote to back it by the deadline of noon on 30 January.