Nearly 400 pupils in the Capital will be left scrambling to find spare places at other city schools after St Margaret's announced it would close in two weeks' time.
The school has gone into administration after struggling with an annual operating deficit of around 500,000 and falling pupil numbers.
Shocked parents were told on Thursday evening the school would close on 29 June.
While some organised protests, others started drawing up a possible business plan to keep the school open.
Parents and Friends Association chair Val Devlin, 40, said: "We have some very smart cookies among us in the parent community and we will not leave this school. We owe it to our children and the teachers too. They have claimed the roll was falling but it actually rose by 19 per cent in the past term."
Liquidator Blair Nimmo of KPMG said he would listen to parents but warned that a rescue was unlikely.
If the bid fails, parents will face the task of trying to get their children into another school in time for the start of the new term in August.
The council's education department is preparing for applications but many of the most popular council-run schools, such as James Gillespie's and Boroughmuir, are already at full capacity.
Other independent schools have been inundated with inquiries already.
More than 50 people gathered outside the school yesterday afternoon to protest against the closure and a campaign website has been set up.
One parent, who did not want to be named, said: "If they've been having concerns, they should have had a meeting and let us know they've had concerns rather than being so underhand and sending it (the e-mail warning of the closure] out so late."
The Evening News revealed last month that the school was having financial difficulties after it imposed a continued pay freeze on teaching staff.
Margo MacDonald, independent Lothians MSP, is calling on the council to consider taking over the running of the school's buildings.
She said: "My basic proposition is for the education department to investigate possible ways of putting to good use what could amount to a possible resource at a time when the economic conditions are likely to prove a handicap to achieving optimum results."