A pressure group has lost a legal challenge against a council's decision to earmark parkland it owns for the site of a secondary school.

Edinburgh City Council is proposing to use the ground, which is inalien-able common good land, within Portobello Park for building a long-discussed new Portobello High School.

Portobello Park Action Group launched a judicial review seeking to challenge the local authority's decision to appropriate the land for use as a school without obtaining the consent of a court for the proposed change of use.

They argued it was unlawful for the council to use the land for the school and it could not do it without the court's permission and sought to have the move set aside.

However, a judge at the Court of Session in Edinburgh has now dismissed their judicial review petition because of delay in bringing the proceedings. Lady Dorrian said by March 2010 "at the very latest" the council had determined that it could lawfully appropriate the site.

She said it would have been open to the campaigners to challenge the decision at that date and added: "A reasonable person knowing all that the petitioners knew, and observing their conduct, would have been entitled to conclude that they had, albeit reluctantly, acquiesced."