Monash Council had tried to introduce vegetative protections for the site but the State Government does not have to follow them.

About 40 of the trees on Department of Education and Early Childhood Development land are almost 20metres tall and more than 50 years old.

After the council met department delegates last week, Mayor Paul Klisaris said an agreement had been struck to preserve two large trees and some smaller shrubs on the site.

He said demolition would start at the site, and at Monash Secondary College in Notting Hill, this week.

A spokeswoman for the department said most of the trees on the site would remain untouched.

"There are two sections on the site [that] will be saved. We can't give exact numbers. It depends on the nature of the building works.

"We won't do anything else without consultation with the council.''

Brandon Park Action Group spokesman John Shrives said any large-scale destruction of the site's 100 mature trees would be an attack on the environment and the community.

"We've expressed through submissions and meetings for the past four years that we want the trees saved.

"Not once have we wavered in our request to save them. It will destroy the area totally, not just for the look of the trees but as a windbreak and a barrier between the commercial area and the residents.''