The Act is stupid and serves no purpose. You should control the use of agricultural land for development by refusing permission, not with spurious restrictions that make life impossible for the owner.
Local authorities are empowered to impose restrictions allowing only agricultural workers to live in designated properties.
This results in lenders refusing to supply mortgages. As a consequence it prevents sale on the open market except to cash buyers, and such properties are typically on the market for years without sale and if sold are at a deep discount to the proper market price (25-30%).
To remove a restriction, owners are told to do a market research survey of the area to find any possible buyers. The result of this survey is then submitted with a planning application, and the Planning Officer decides if the restriction will be removed.
The net effect is that mobility is restricted and a quick sale impossible. It also devalues the property and places the owner and his children at a significant disadvantage. I was even told that my son would have to give up residence in my house if I died – he would own it but not be able to live in it while the restriction remained!!!