Police Powers and Responsibilities Act 2000

the nature and seriousness of the suspected offence or terrorism;

the extent to which issuing the warrant would help prevent, detect or provide evidence of, the offence or terrorism;

the benefits derived from any previous covert search warrants, search warrants or surveillance device warrants in relation to the relevant person or place;

the extent to which police officers investigating the matter have used or can use conventional ways of investigation;

how much the use of conventional ways of investigation would be likely to help in the investigation of the matter;

how much the use of conventional ways of investigation would prejudice the investigation of the matter;

any submissions made by a monitor.