A councillor will call for a council tax freeze after a report recommended a three per cent hike for Band D properties.
Ian Scott will also seek support to stop proposed rent rises.
The Shetland Central member has spoken ahead of council meetings next week.
“I’m going to propose that we freeze the council tax and rent rises,” Mr Scott said.
“Our reserve fund is absolutely enormous.”
It follows a warning from Shetland Islands Council’s head of finance Jamie Manson that failing to increase charges would result in an additional £300,000 draw from reserves.
Mr Manson has called for continued prudence to help cut the reliance on council reserves in the next financial year, which has already reduced by half since 2020.
But the authority is still expected to withdraw over £5 million from reserves.
Spending is expected to reach £139.6 million during the next year, but income is only forecast to be £134.5 million.
“The continued reliance on reserves, over and above the expectations of our medium-term financial plan, indicates the council is not yet in a financially sustainable position.”
Mr Manson states that, if the council could not use its reserves to help balance the budget, the council tax increase could – in theory – be set at 24 per cent.
But Mr Scott insisted: “We’ve got £460 million in our reserves – that’s the latest amount in the third quarter of our financial year.
“By April, it could be nearly half a billion. And we’re being told that to withdraw another £300,000 is unsustainable.
“Who in their right mind can honestly say that another £300,000 out of £460 million is unsustainable?”