Castlebrae Community High School was saved from closure at the 11th hour in a dramatic U-turn when councillors voted against the advice of education officers by deciding to keep the school open.
The Craigmillar site may now operate as a vocational training hub under the direction of senior staff from neighbouring Portobello High.
Officials are exploring plans that would see Castlebrae become an annex of Portobello High, where pupils at Castlebrae were to be offered places after the proposed closure.
The council said it was looking at options for the new school but added it was too soon to say what they might be or how they would work.
Chair of Portobello High School Parent Council, Paul Smart, urged the council to meet with parents to explain what impact the annex would have on the pupils.
The 55-year-old from Willowbrae, who has a son in fourth year at Portobello High, said: “We would look to the council to give us a clear opportunity to speak with them about what this might mean for our children. I’m not entirely opposed to the principle of Castlebrae becoming an annex of Portobello High but in practise you would need to have very careful management.”
Director of children and families Gillian Tee has been given three months to draw up plans for Castlebrae’s future before a consultation begins.
A vocational training hub could include community facilities and would remain open until a new school was delivered in Craigmillar by 2020.
It is understood city chiefs are considering putting the running of any annex in the hands of headteachers at Portobello in a cost-cutting move.
Conservative group leader Councillor Cameron Rose said: “This is a last-minute decision which has been cobbled together without any planning. It seems to me that the administration are now starting from scratch. There will be costs whichever plan they now follow, which will impact on other schools and council budgets.”
A council spokeswoman said: “Following the council decision, we will be looking at a variety of options for the new school.
“It is too soon to suggest what these might be and how they might operate. However, we will be working with the school and the community to develop plans and a report will go to committee outlining these in time. Any future plans will be fully consulted on with local communities before a decision is made.”