The letter to Fergus Ewing MSP outlines the disproportionate impact cuts will have on rural locations.
Sites that will be affected are: the Brodick Castle on the Isle of Arran, where current proposals will result in a net loss of 20 jobs, and the Threave Estate, home to Castle Douglas.
Staff working on the Isle of Arran are permanent seasonal staff and would have been expecting to return to their jobs in March or April.
The proposed cuts on Threave would impact the area’s ambition of becoming a natural nature reserve, as the ranger service would be reduced. Rangers currently provide a vital role in maintaining the estate and relationships with tourists, local communities and schools.
Prospect negotiations officer Ian Perth said: “While we respect an organisations like the trust need to consider changes from time to time, employers can do this by working in partnership with their staff. Instead it seems the Trust have are Proposing to delete 78 roles, and create over 60 new job titles.
‘’Our union want the Trust to be successful and viable but compulsory redundancy is a very blunt instrument and should be used very sparingly by when spending charity funds. Organisations should try to make changes in partnership with staff.’’