Belmiro de Freitas says he's been trying, unsuccessfully, to renew his lease. It expires after 21 years at the end of this season.
The premises at the foot of Fermain Valley are owned by the States of Guernsey.
Since 2003, the cafe and seafood bistro have been leased by Bel de Freitas.
His efforts resulted in an accolade from The Guardian newspaper as second best beach cafe in Europe, in 2007.
Bel says some regulars are dismayed that 2024 may be his last season at Fermain:
"Some of them have been crying outside because they don't want the island to change. Changing iconic locations like this, there's a balance to go with it."
The change envisaged is outlined on a Guernsey property company website. The States, as landowners, describe it as a unique opportunity to enhance the offering at Fermain with the potential to build to two, or even three storeys, retaining the bistro and cafe element.
Belmiro de Freitas says he's been trying to renew his lease for three years but has had no luck:
"Last year we went back. I put a law firm on it and said look, deal with this please, it's almost finished (the lease) and I need to renew it, but they turned around and said no, and that was only a few months ago."
We have approached the States for comment.