Section 135 (1) of the Mental Health Act is the power to remove a person from a dwelling if it is considered they have a mental disorder and that they may be in need of care and attention for this. With the agreement of the person they can be assessed at the dwelling or removed to the place of safety for the assessment to take place there.
The process is for the Approved Mental Health Professional to present evidence at a Magistrates Court in order to obtain a warrant which will authorise the police, an approved mental health professional and a registered medical practitioner to gain entry to the premises in order for assessment to take place there or for the person to be removed to a place of safety.
Once granted the Approved Mental Health Professional with the police and a registered doctor can enter the property and formulate their assessment or remove to the place of safety if required.
Once the warrant is executed (it can only be executed once) a copy of the warrant will be provided to them, a copy will also go to the police and a third copy must be returned to the court. There are no other official rights as such but obviously if the assessment progresses to a detention under the Mental Health Act then those rights will be invoked at that stage.
The court can also issue another warrant (135(2) for service users already detained who have absented themselves from hospital and are in a private dwelling. This warrant is applied for by the police or an authorised person and will authorise them to gain access to the property and return the service user to the hospital where they are detained.