In an email to parents on Thursday, Principal Anne Coutts asked parents to provide feedback to the school on the proposal.

Currently boys are enrolled from pre-school to Year 2.

Prior to this year, Canberra Girls Grammar was closely aligned with Canberra Grammar – an all-boys school. They both took girls and boys up until Year 2 and then provided a reciprocal enrolment guarantee for Year 3.

But Canberra Grammar's decision to move to co-education had resulted in an end to the co-operation between the schools and Canberra Grammar has enrolled 28 girls across Year 3 and 4 this year, with intakes to follow in Year 7 and Year 11 next year.

Ms Coutts said her school was considering the move to extend boys into Year 3 as a direct response to enquiries about how parents could manage their boy's schooling if they wish their sons to move to an all boys' school. Both single-sex boys schools in Canberra (nearby independent Catholic schools Marist and St Edmund's) begin classes at Year 4.

In that sense, Canberra Girls Grammar could fill in that gap year,

"At present boys in CGGS leave at the end of Year 2 which leaves those wishing to attend a boys' school with an unresolved Year 3," Ms Coutts said.

She told parents "Please be assured this is not a signal that CGGS is going to be co-ed in the future. We are simply responding to this request".

She also stressed no decision had been made and the school would consider the wishes of parents through its consultation process.

"We have made no decision, this is a consultation process. We will decide when we have heard the views of all parents in our Early Learning Centre and Junior School.

Parents have until Friday March 11 to provide their responses to the idea.