Campaigners trying to save a Catholic school in Bristol from closure say they have a 70% to 80% chance of success.
St Ursula's in Westbury-on-Trym went into administration after a bid to make it a non-denominational academy school was rejected by the nuns who run it.
The school, which is fee-paying, has been hit by falling numbers of pupils.
Chris Thurling, of the campaign to keep the school open, says the academy bid can succeed with private money and "people power can save the school".
The Sisters of Mercy order, which has run the school since its foundation in 1896, says it will not block any plan for the school becoming non-denominational - but it will only continue to finance the school if it remains Catholic.
A Christian educational trust, Oasis Community Learning, wants to save the school by turning it into an academy.
But the Sisters of Mercy said there was insufficent funding to secure the long-term, viable future of the school.
Oasis says it remains in discussions with the order over the future of the school.
Mr Thurling, who chairs a group of concerned parents, said: "I'm being really optimistic and I can say we have a 70 to 80% chance of success.
"The key players I'm talking to are making positive noises.
"It would be a tragedy for the city to lose St Ursula's, particularly if it's to become an academy available to the wider community for free."
The campaign is pinning its hopes on fundraising from the corporate sector and among parents.
So far, just over £100,000 has been raised by supporters and Mr Thurling says the campaign has been offered an interest-free loan.
Forty staff lost their jobs and 160 pupils remain without places for the coming academic year after the school was put into administration on 4 August.