Public Law: Proportionality

Traditionally, administrative action in the UK has been subject to three grounds of review. Lord Diplock, in the GCHQ case, reiterated these and labelled them ‘procedural impropriety’, ‘illegality’ and ‘irrationality’. The test to establish whether a decision was irrational had been subject to a particularly large amount of litigation and, consequently, debate. Proportionality, a doctrine applied as a ground of review across continental Europe, necessarily grants judiciaries’ wider powers to consider the merits of a decision. The decision made must be proved to have been necessary to meet a legitimate aim, and the most reasonable way of doing so. Consequently it is a far more stringent test for irrationality than Wednesbury. Since the UK joined the European Union in 1973, judges have been required to apply the proportionality test in cases with a European dimension and increasing pressure has been placed upon the judiciary to incorporate the test into domestic administrative law.

The modern procedural definition of the proportionality test is relatively clear. Tom Hickman, identified the most common formulation as a three-part procedure. The reviewing court must consider: Whether the measure was suitable to achieve the desired objective, it is necessary for achieving the desired objective. Whether, even so, the measure imposed excessive burdens on the individual it affected. In the UK, the doctrine has often been defined in contrast to the recognized ‘irrationality’ principle and the test coined in Wednesbury. Lord Steyn argued that although ‘there is an overlap’ between irrationality and proportionality and ‘most cases would be decided in the same way’, the ‘intensity of review’ is ‘greater’.

Since the courts first began applying the doctrine academic and judicial suggestions that proportionality should be in some way incorporated into domestic UK law have been regular. Moreover, pressure for reform has increased since the assent of the HRA (1998), which