The UK Government has committed to keeping farm funding at the same level to 2024/25, the end of the current parliament.
Direct payments, Bew Review uplift cash and other funding streams are worth £620 million to Scottish farming every year.
However, increasing production costs and broader uncertainty around global events mean that fewer farm businesses will turn a profit without guaranteed support.
NFU Scotland is certain that active farming and crofting can deliver on the objectives, but only with the required funding.
In a bid to extend the funding commitment window, rural constituency MPs Andrew Bowie, David Duguid and John Lamont have sought a meeting with Exchequer Secretary Helen Whately. They have also backed calls for the Scottish Government to ring-fence the block grant Scotland receives for farming, via the Less Favoured Area and AECS schemes.
The intervention follows briefings from NFU Scotland figures and Westminster's all-party farming group chairwoman Fay Jones.
Andrew Bowie, MP for West Aberdeenshire and Kincardine said: "The UK Government committed to 2024 because there will be a new system of support by 2028. And it will be much better than the Common Agricultural Policy ever was for Scotland. However, no one at that time envisaged the war in Ukraine and the impact that would have on everything farmers need, from diesel to fertiliser to animal feed.
"We're asking HM Treasury to make one change to protect our food supply at an uncertain time."
David Duguid, MP for Banff and Buchan said: "I hear regularly from local farmers and industry experts who have given clear examples of the challenges our farmers face, right now. The farm survey for 2020 showed most farms would have made a loss without the guaranteed payment.
"The industry is modernising at a rapid pace. Diversifying and decarbonising is a major part of what they do. But we need to protect food security, and this one change will help farm businesses manage their finances."