Prospect also described the decision to push ahead with a major restructuring plan as madness at a time when the Trust’s board lacks a director of conservation services, the area most at threat by the proposals and the guiding principle behind the creation of the heritage body.

On behalf of 400 of the Trust’s 500 permanent staff, Prospect national secretary Alan Denney said: "NTS claim their proposals will create 22 new posts. But this still amounts to the potential loss of one tenth of its workforce and hundreds of years of collective conservation knowledge and experience. This is a case of taking your eye off the ball and scoring an own goal."

Denney said the guiding principle behind the organisation’s creation in the 1930s was to ‘promote the permanent preservation of places of historic or natural interest or natural beauty,’ meaning its core objective is conservation on behalf of the nation.

"Yet the Trust is driving through these cuts when its board lacks a leader to oversee its raison d’être." The job description of the director of conservation services lists responsibility for ‘delivering the NTS core objective to be Scotland’s leading conservation organisation’, he said.

The union is calling on the Trust’s board to use the consultation period between now and August to rethink the proposals and explore alternative options. Prospect members will meet with NTS management on July 19 to voice their fears for the future of the heritage body and discuss rebalancing the proposals.

"We understand that the Trust may need to become more businesslike in some areas," said Denney. "But it should never be a Disneyland style visitor attraction or become ‘Tesco Historic’. If it fails to secure its core objective it will fall into terminal decline, losing the support it has maintained over the years from a longstanding and loyal membership."