The right to quiet enjoyment is implied into every tenancy in England, even if it's not written in your tenancy agreement. It means your landlord can't enter the property without your permission (except in genuine emergencies), can't harass you into leaving, can't disconnect utilities, can't remove your belongings, and can't carry out work that unreasonably disrupts your use of the property.
Your landlord must give at least 24 hours' notice in writing before entering the property for inspections or non-emergency repairs, and they must visit at a reasonable time. However, the right to quiet enjoyment is absolute, meaning you can refuse access even if adequete notice is given, and your landlord or their agent can't enter without your consent. This is the case regardless of what your tenancy says; you cannot sign away your statutory rights.
If your landlord repeatedly enters without permission, turns up unannounced, makes threats, or takes actions designed to force you out, such as changing the locks while you're out, this may constitute harassment and illegal eviction, both of which are criminal offences under the Protection from Eviction Act 1977.
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