Welsh language campaigners say a £284 million investment for Cardiff schools is not doing enough to support the growth of the language.
The plans include building three English language secondary schools.
But Cymdeithas yr Iaith Gymraeg say this still will not answer the increase in demand for Welsh language education.
Cardiff council are to discuss the plans on Thursday.
The scheme, put forward jointly by Cardiff Council and the Welsh Government, are part of the council’s 21st Century Schools Programme, which aims to modernise education in the city. Willows, Cathays and Catonian High Schools will all be rebuilt to accommodate more pupils.
Graham Norsworthy, who works for Cymdeithas Yr Iaith says his organisation “want every child in Wales to leave school with the ability to speak Welsh and this investment will not deliver on that”. He says it is contradictory that the council and Welsh Government are investing more in English language education, despite the Welsh Government’s own policy stating they want a million Welsh speakers by 2050.
But the council say their vision for education and learning in Cardiff shows a clear commitment to ensuring enough spaces for children who want to be educated in Welsh. Labour councillor, Sarah Merry who is the cabinet member for education says: “Since 2012 we have significantly increased capacity in Welsh-medium education across the city and we are in the process of building a further three new Welsh-medium primary schools”.
The plans, if approved would be the largest investment into education in Wales.