The local authority believes the land behind the site is needed for housing
Castletown Commissioners has agreed to lobby the government to try to progress the development of a new Castle Rushen High School.
Jimmy Cubbon's motion to write to the chief minister and education minister said the town can't grow 'naturally' because of the sea and the airport, and is far behind the level of Peel and Ramsey.
At its meeting last night, board members agreed that the land at the back of the school needed to be used for housing otherwise the town's population will 'stagnate'.
Mr Cubbon says the only land which can be 'reasonably' used to support the growth of the town is behind the high school.
Local Democracy Reporter Emma Draper spoke to him after the meeting: