SINN Féin's Pat Sheehan last night called on the education minister to do more to "encourage and facilitate" Irish medium education in Northern Ireland.
The West Belfast MLA also said Michelle McIlveen needs to ensure that Irish medium schools "have their accommodation needs met".
It comes after it was reported that Coláiste Feirste, the north's biggest Irish-medium school, is facing acute accommodation pressures.
The west Belfast school has revealed it may have to use its staffroom and sports facilities as classrooms from September as it expects to have around 900 pupils in the 2022/23 school year.
The existing school building was designed to accommodate 600 pupils.
Mr Sheehan last night said more support was needed for the sector, which is facing increasing demand.
"Irish medium is the fastest growing education sector in the north with over 7,000 young people now learning through the medium of Irish here," he said.
"Coláiste Feirste was set up to accommodate 600 pupils, they are expected to welcome 900 this Autumn.
"Over 60 per cent of Irish medium schools reside in so called temporary prefab or modular accommodation.
"The rapid growth of Irish medium education is expected to continue with enrolment figures set to hit 10,000 pupils in the coming years.
"There is a duty on the Department of Education to encourage and facilitate Irish medium education and the minister needs to realise this duty isn’t optional.
"The minister has an obligation to engage with and address the issues facing Irish medium education."
The Department of Education was contacted for a response.