[Thanks to Claire Darwin of Matrix Chambers for preparing this case summary]
Wallis & GHP Securities Limited v Justin Meredith, or the case of the "two burly men with Eastern European accents" as it will doubtless become known, is authority for the proposition that if an employee sends a letter alleging unlawful conduct by the employer to the employer's own solicitor, this does not amount to a real and substantial act of defamation.
The letter had been sent in the context of a commercial dispute, and the allegation (that the employer had sent the two burly men to visit the employee's home) was denied by the employer. This denial was repeated by his solicitor in correspondence. Accordingly the High Court (QBD) held that it was doubtful that the employer's solicitor had thought any the worse of his client on account of the allegation, and no need for vindication of the employer's reputation arose.
Clarke J observed that solicitors routinely receive publications about their own clients which are defamatory. However such publications are likely to be covered by qualified privilege or perhaps absolute privilege, both of which provide a defence to an action for defamation.