An overcrowded school which teaches some of its children on a converted double-decker bus now faces losing £40,000 in funding.
Ysgol Bryn Hedydd has 472 pupils, despite being built to house just 290.
And it has been told it must manage with even less cash in the coffers.
Parents and teachers are calling on the local council to reverse the cuts.
A tweet from the primary school, in Rhyl, North Wales, said it has lost more than £90,000 in funding since 2015.
Petition organisers say the cuts could affect teaching and non-teaching staff, as well as resources and equipment.
Chris Ruane, Labour MP for Vale of Clwyd: said: “It was troubling to hear of the measures they are having to take in order to try and balance the books.
“Our children’s education should be the priority as it not only impacts on their future life chances, it impacts on so many other areas such as health.”
Denbighshire Council said: “Schools such as Ysgol Bryn Hedydd are not alone in facing financial challenges.”
