My landlord's family keep coming into our garden. Can we stop them?Beta*

If the garden is part of what you rent, it's part of your home and the same rules apply as inside. Nobody, including the landlord or their relatives, can come in whenever they want. Check the tenancy agreement and the advert to confirm the garden is included. Then write to the landlord saying the visits must stop, and that any visit needs your agreement and at least 24 hours' notice. Keep a dated log of each visit. If it carries on, the council's tenancy relations officer can step in, because repeatedly interfering with your peaceful enjoyment of your home can be harassment.

Sources: Shelter: harassment by a private landlord