In Ofcom v Information Commissioner [2010] UKSC 3 the Supreme Court was asked to consider how public authorities should approach the exceptions to disclosure set out in the Environmental Information Regulations 2004 (EIR).  Most of these exceptions are subject to a public interest test.  The public interest in maintaining an exception has to be measured against the public interest in disclosure.  Unless the public interest in maintaining the exception outweighs the public interest in disclosure, the information must be disclosed.

But what happens if there are a number of exceptions in play?  Do you look at each exception in turn, assessing the public interest in maintaining that exception as against the public interest in disclosure?  Or do you aggregate all of the exceptions, assess the combined public interest in maintaining them, and measure that combined interest against the public interest in disclosure?

In the Ofcom litigation, the Court of Appeal had decided in favour of aggregation.  The Supreme Court was inclined (by a 3-2 majority) to uphold that decision.  But the Supreme Court also recognised that the answer was unclear, and depended on the construction of Directive 2003/4/EC.  So the Court has referred the issue to the European Court of Justice.

There is now a practical difficulty:  in cases where the aggregation point might make a difference to the outcome, what should the Tribunal do? Should it follow the Court of Appeal?  Should it wait for the ECJ?  Or should it reach its own view on how the legislation should be interpreted?  And Ofcom is an EIR case: what about aggregation under FOIA?

In practice nobody will want the outcome of their case to turn on a point that may not be resolved for some years.  It will be much more attractive for parties to argue that aggregation makes no difference to the outcome of their case.