Most Scottish councils do not know how much open space is being lost to PPP school developments, it has emerged.
Plans for Dingwall Academy in the Highlands have raised objections
First Minister Jack McConnell said a balance must be struck between losing green spaces and building new schools.
But councils do not keep figures on the area of playing fields, parkland and open space they are losing.
A study by campaigners in South Lanarkshire has claimed Scotland is losing an equivalent of 180 football pitches to PPP developments.
The report was put together by Professor John Bachtler, who is angry about plans to combine Cathkin High School and Rutherglen High School on part of Holmhills Wood Community Park.
The Holmhills Wood Community Park Action Group (HWCAG) report highlights the loss of school parks, playing fields and neighbourhood open space.
The report states: "The HWCAG survey has found evidence that councils are prepared to sacrifice green space in order to satisfy the preference of developers to build new schools on greenfield sites.
"Parkland, community playing fields and informal 'kickabout areas' are all being built on, regardless of the views of local communities."
Examples cited included the Holmhills project in South Lanarkshire, six projects in Stirling, Dingwall Academy in the Highlands, Denny High School in Falkirk, Alloa Academy in Clackmannanshire and three projects in North Lanarkshire.
PPP is being used to upgrade schooling provision
Three years ago ministers advised councils to survey and audit their open space.
The BBC's Newsnight Scotland programme has seen written responses from all the councils which showed that when asked under freedom of information legislation for their figures on loss of open space, few could provide a detailed reply.
The first minister made the call for balance in the system after the Green Party raised the issue with him at Holyrood on Thursday.
But Prof Bachtler wants to know how councils can balance open space loss if they do not know what is being lost.
A spokesman for council group the Convention of Scottish Local Authorities insisted: "This information will be held by local authorities and I would be very surprised if a council does not know what open space it has in its area."
The Scottish Executive said work was under way to evaluate the situation.
A spokesman said: "At least half of the local authorities in Scotland have either completed or are working on their open space audits and strategies."
But the HWCAG study concluded: "In light of the evidence published in this report concerning the national picture on open space loss, there is a strong case for the Scottish Executive to review all approved PPP planning applications that involve open space loss with a view to establishing ways in which councils can be required to ameliorate green space loss at community level."