A defendant may present evidence that a claimant has a bad reputation in mitigation of damage as per the rule established in Scott v Sampson (1882) 8 QBD 491. What sort of evidence may be admitted was considered by the Court of Appeal in Burstein v Times Newspapers  1 WLR 579. This case concluded that "evidence of directly relevant background context" was admissible in mitigation.
The Burstein principle was reviewed by the Court of Appeal in Turner v News Group Newspapers  EWCA Civ 540. In this case the Court of Appeal made the following observations:
- A Burstein plea could put forward evidence of the claimant's general reputation, but evidence of specific acts of misconduct would generally not be admitted on the basis that this could lead to 'a trial within a trial'.
- Evidence of past conduct may be particularly relevant where the defendant has made an offer of amends and that evidence may be used to assess injury to a claimant's feelings.
- There is no need for a defendant to show that he had the directly relevant facts in mind when publishing the defamatory statement.
The Court of Appeal judges were split as to what 'directly relevant background context' would encapsulate. Keene and Pill LJJ held that Burstein evidence needed to be evidence "which is so clearly relevant to the subject-matter of the libel or to the claimant's reputation or sensitivity in that part of his life that there would be a real risk of the jury assessing damages on a false basis if they were kept in ignorance of the facts to which the evidence relates." By contrast, Moses LJ preferred the more simple construction that evidence should be directly relevant to a claimant's conduct or reputation in the particular sector to which the defamatory statement related. Direct relevance to a particular sector of the claimant's life should be assessed by starting with a careful identification of the sector of the claimant's life to which the defamatory material relates.
Therefore, it appears that for a Burstein plea to be successful, the proposed evidence will need to have some degree of connection to the subject matter of the defamatory statement in terms of the subject matter but also temporally. In other words, the more different the subject matter of the Burstein evidence is to the defamatory statement, and the further away in time, the less likely it is to be admitted by the court.
If the Court is able to conclude that a claimant's reputation is so undeserving of protection (in spite of the fact that their defamation claim has been successful) then it may only award nominal damages. An example of this is Grobbelaar v News Group Newspapers  UKHL 40. In this case former Liverpool footballer Bruce Grobbelaar brought a defamation action against the defendants for a series of publications in the Sun newspaper alleging that he had fixed or agreed to fix football matches for money. The jury at first instance had concluded that Mr Grobbelaar had accepted bribes, but that it had not been proved that he had thrown matches. The House of Lords (as it then was) awarded Mr Grobbelaar the sum of £1, on the basis that "it would be an affront to justice if a man who accepts bribes to throw matches should obtain damages for the loss of reputation as a professional sportsman merely because he cannot be shown to have carried out his part of the bargain." By his own conduct Mr Grobbelaar had "destroyed the value of his own reputation" and could only be awarded nominal damages.
The Grobbelaar case is an extreme example, but it does show the potential strength of adducing evidence as to the claimant's bad reputation and by doing this a defendant can significantly reduce damages it may have to pay in a successful defamation claim.