During their trials, the three MPs (David Chaytor, Elliot Morley and Jim Devine) had each separately argued unsuccessfully that there was no case to answer as the doctrine of parliamentary privilege covered the expense claims and could not be the basis of criminal charges.

The Supreme Court, comprising nine judges to reflect the importance of the matter, heard arguments over two days in October 2010 before unanimously rejecting the submission that Parliamentary privilege under either the common law or the Bill of Rights 1689 protected the defendants from prosecution.

[5] Each charge was brought in relation to allegations that each defendant had misused the Parliamentary expenses system and dishonestly claimed substantial sums of money to which they were not entitled during their terms in Parliament.

A single hearing was held to determine the matter, in which Mr. Justice Saunders ruled that the politicians were not afforded protection by parliamentary privilege.

Lord Clarke's extra words, his thus obiter judgment – not concurred nor dissented in by the rest of the panel – were that once waived or relinquished by Parliament, no MP or peer can rely upon exclusive cognisance.