English medium streams will be phased out in state schools in one Welsh county. Cyngor Gwynedd plans to make Welsh the principal language of education in every school it administers.

The authority is planning the first major review of its Welsh language education policy in more than four decades. The Draft Revised Education Language Policy will come before the council's Education and Economy Scrutiny Committee meeting nest week on Thursday, April 10.

The shake-up will see Welsh becoming the significant language used to teach children in all the county's schools. Ysgol Friars, Bangor, Ysgol Uwchradd Tywyn, Tywyn and Our Lady's School, a Catholic primary, in Bangor are categorised as "Category 3T schools" or schools "schools in transition" which are moving towards full Welsh medium provision. Read the biggest stories in Wales first by signing up to our daily newsletter here

Welsh is already the predominant medium in the rest of the county's 90 plus educational establishments. They are considered to be in the Welsh Government's Category 3 – schools that already offer a significant amount of Welsh medium provision, with Welsh being the main language of internal communication.

Children who move to the county from non Welsh speaking areas will be referred to attend Gwynedd's Immersion Education System. The main changes are:

• All pre-school education settings will be provided through the medium of Welsh.
• All pupils in the Foundation Phase until the end of Year 2 will be taught and assessed through the medium of Welsh.
• Schools will provide opportunities for pupils to use the Welsh language regularly, inside and outside the classroom, in a curricular and extra-curricular manner.
• From Year 3 onwards, at least 80% of the pupils' educational activities (both curricular and extra-curricular) will be in Welsh.
• Pupils' grasp of Welsh will continue to be developed, giving attention to the development of their skills in both languages. From Year 3 onwards, English will be introduced as a subject and cross-curricular learning medium.
• In secondary schools Welsh will be the main language of education for all pupils up to 16 years old.

English will continue to be introduced as a subject and learning medium of some cross-curricular elements.

Schools are expected to ensure that all pupils (Years 2-9) who are latecomers and new Welsh speakers are referred to attend Gwynedd's Immersion Education System. Children and young people with additional learning needs (ALN) will receive equal linguistic opportunities in accordance with the policy.

The council says the new policy is in line with Welsh Government's Welsh 2050: A Million Welsh Speakers' strategy. The proposed changes will have to be scrutinised and debated in the council's cabinet and full council. A public consultation will also have to be held.

The council, in a report published today, stated: "This policy is an attempt to set Gwynedd's ambition to ensure that the county's children and young people grow up to be proficient users of the Welsh language and develop bilingual or multilingual skills within our education system."