MSPs will be asked to support a private bill at Holyrood to make way for a replacement Portobello High School in Edinburgh.
Opponents of the plan say there will be dire consequences for green spaces across the country if politicians accept the proposal.
The initial plan for the school stalled when it was ruled at the Court of Session that the city council’s preferred site, Portobello Park, is “inalienable” common good land.
The council now has to secure parliamentary approval to change its use to allow construction.
Supporters of the plan urge the Scottish Government to work with the council to sort out the “legal loophole” which they say is holding up construction.
But a spokesman for Portobello Park Action Group said: “If the park loses its status as common good land, a dangerous precedent will be set for other green space throughout Scotland.
“A positive vote would provide authorities with an easy option to bypass legal protection of common good land and take it for any purpose they wish.
“Other Scottish parks that are common good land, such as Bogton Park in Forres, Westerton Park in East Dunbartonshire, Coo’s Green in North Berwick and Cowan Park in Barrhead, are already earmarked for development, which will be made easy if this bill is passed.”