Garden staff and rangers living in National Trust properties are set to lose their tied accommodation, says the conservation group, which is carrying out a major review.
Between 120 and 190 staff, some of whom have worked for the trust for decades and pay peppercorn rent, could lose the roof over their heads. A quarter of the total are garden staff.
A spokesman insisted that the initiative was not a cost-cutting exercise. "The review of all staff accommodation is for tax-compliance issues and the need for equitable work conditions," he said.
Quitting houses will be phased over four years and staff can appeal and will be compensated. Amounts have not been finalised but will vary on local rents and council taxes, he added.
It is thought that some people may receive several thousand pounds in compensation. "This will be on a case-by-case basis. There's no blanket policy. Accommodation must be deemed essential for 24-hour security to attract a more generous tax regime. But unlike schools and residential homes it has become harder to justify for our properties," said the spokesman.
"Meanwhile, new staff do not enjoy the same benefits as those in years gone by who received accommodation. We want to be fair to all employees. The response so far has been mixed. Some welcome the opportunity for change, others have concerns."
One ranger told The Independent: "It's awful for us, but we're scared to say anything in case we lose our jobs as well. They've gone back on our deal - they want to rent the houses for the market and get us out."
But the National Trust's Surrey Hills board member David Kennington said while the public feel reassured by the presence of staff, it is no longer a reason to provide houses. The RSPB and Forestry Commission did away with tied housing "donkeys years ago".
Prospect negotiations officer John Stevenson said: "The trust has a paternalistic reputation and is a good employer. But the world moves on and it is trying to move into that modern world. There are commercial pressures and it needs modern employment relationships. Our job is to mitigate the consequences and to ensure every member gets the best possible outcome."