Funding for the Scottish Government will fall by 4.5% in real terms next year, according to John Swinney.
The deputy first minister attributed the decrease to spending plans set out by the UK Government as well as inflation forecasts by the Bank of England.
Swinney warned that if inflation rises significantly, the resources available to ministers at Holyrood will “erode even further”, as he urged the new prime minister to act decisively.
Liz Truss appears likely to be named as the country’s next prime minister on Monday.
On Sunday, Truss pledged that she will “act immediately” on bills and energy supply if she is elected as prime minister.
Swinney insisted that further spending cuts to the Scottish budget would be “disastrous and would cost lives”.
“With the new Prime Minister due to be appointed this week it is vital that the UK Government now acts decisively to tackle this ongoing crisis,” said Swinney.
“The Scottish Government is continuing to do everything within our powers and resources to help those most affected; however, the powers and resources needed to tackle this emergency on the scale required lie squarely with the UK Government.
“Further spending cuts to Scotland’s budget from the UK Government would be disastrous and would cost lives.”
First Minister Nicola Sturgeon will this week set out her government’s plans for the year ahead in a statement at the Scottish Parliament.
On Wednesday, Swinney will also make a statement at Holyrood on how the Scottish Government will meet the costs of rising pressure on public sector pay.
It comes after Sturgeon acknowledged that there would be “difficult decisions to make” after a £600m pay deal was made to local government workers.
“This year’s Programme for Government is set against a backdrop of economic upheaval that has not been seen for a generation, already impacting people, businesses, public services and the third sector across Scotland,” said Swinney.
“For that reason, this is a different Programme for Government – one that is subject to the outcome of our Emergency Budget Review and its implications for our Budget for 2023-24.
“The UK Government’s existing spending plans, coupled with Bank of England inflation forecasts, mean that the Scottish Government’s funding will fall by 4.5% in real terms next year.
“If inflation rises significantly higher, the resources available to us will erode even further at the very time when costs are increasing.”