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Necessity and Proportionality


The tests of necessity and proportionality are important tests. When considering proportionality, the Commissioner takes it as a priority that any intrusion into privacy must be fully justified by the necessity to gain intelligence or carry out the activities being authorised in the interests of the United Kingdom.

When using the capabilities and techniques available to them to gather intelligence, the agencies must always aim to take the course of action that is effective, minimally intrusive into privacy, and proportional to the threat they have identified. Before using intrusive methods to gather intelligence, the agencies must justify to the relevant Secretary of State that what they propose to do is both:

The relevant Secretary of State needs to be satisfied that the information that is expected to be obtained could not reasonably be obtained by other, less intrusive, means.

The intelligence agencies must take care to ensure that they apply for warrants only where the threshold is clearly met.

As part of his oversight the Commissioner ensures that the agencies’ activities are: necessary to protect national security, for the prevention and detection of crime or the economic well-being of the United Kingdom; fall under one of their statutory functions are/were authorised by the relevant senior official or Secretary of State; and are proportionate including that:



Last updated: 11 Sep 14