This Morning Star article describes attempts by Labour politicians to make it easier to prosecute 'sex-for-rent' arrangements, where landlords "demand sex from tenants in lieu of rent".
The article includes the following paragraph:
Under current legislation, victims must be legally defined as prostitutes, which is thought to be a deterrent to victims coming forward since they may fear that it will adversely affect their future.
Under what law must victims be legally defined as prostitutes in order for a prosecution to take place?