The Three Defamation Defences Every UK Journalist Must Know

Why 'I Published the Truth' Is Not Enough — The Serious Harm Test Explained

Many journalists believe that accuracy is a complete shield. If what they wrote is factually correct, they reason, a defamation claim cannot succeed. That belief is wrong, and costly.

The Defamation Act 2013 introduced a threshold requirement that must be satisfied before a claim can proceed at all: the publication must have caused, or be likely to cause, "serious harm" to the claimant's reputation. For companies, the harm must be serious financial loss. This threshold was designed to filter out trivial claims, and it does — but it does not mean truth alone is a safe harbour. A claimant who can demonstrate that an accurate story still caused serious reputational injury has cleared the threshold, and the journalist then needs a proper defence.

That is where the three statutory defences under the 2013 Act come in. Each has its own requirements, its own evidentiary demands, and its own failure modes. Understanding them before publication — not after you receive a legal letter — is the professional standard.

Defence 1: Truth — What You Must Prove and What Records to Keep

Section 2 of the Defamation Act 2013 replaced the old common-law defence of justification with a statutory Truth defence. The defence applies where the journalist can show that "the imputation conveyed by the statement complained of is substantially true." The word "substantially" matters: you do not need to prove every minor detail, but you must prove the sting of the allegation.

This means your records need to match your claim. If the story alleges that a councillor misused public funds, your documentation must substantiate that allegation — not merely suggest it. Contemporary notes, source declarations, documents, emails, and any corroborating materials should be preserved the moment a story has publication potential. Defence lawyers will ask for everything, and a gaps between what you published and what you can prove is where claims are won.

Where a publication contains multiple defamatory imputations and one cannot be proved, the court assesses whether the unproved allegation materially injures reputation beyond what the proved allegations already justify. The defence can still succeed — but only if you have planned for this possibility.

Defence 2: Honest Opinion — Comment Versus Fact and the Reynolds Legacy

Section 3 of the Act provides the Honest Opinion defence, which replaced the old fair comment rule. It covers statements of opinion rather than statements of fact. To rely on it, three conditions must be met: the statement must be an expression of opinion, it must indicate — explicitly or implicitly — the factual basis on which the opinion rests, and an honest person could have held that opinion based on those facts.

The practical distinction between comment and fact is where most mistakes happen. Writing that a CEO "broke the law" is a statement of fact requiring proof. Writing that a CEO's conduct "falls far short of the ethical standards any reasonable board should demand" is opinion — provided you have shown the factual conduct that grounds that view. The clarity of the factual foundation is everything.

The defence does not require the opinion to be fair, moderate, or even widely shared. It requires that an honest person could hold it. This is deliberately generous — it protects robust and provocative commentary. But the protection disappears if the defendant did not actually hold the opinion or if the stated factual basis is false.

Defence 3: Public Interest — Section 4, Responsible Journalism, and the Paper Trail

Section 4 of the 2013 Act encodes the public interest defence, replacing the common-law Reynolds framework. Two elements are needed: the statement must have been on a matter of public interest, and the journalist must reasonably have believed that publishing it was in the public interest.

"Reasonably believed" is judged objectively. Courts ask not whether the journalist thought publication was justified, but whether a reasonable journalist would have. The guidance from case law — much of it inherited from Reynolds — points to a cluster of factors: the seriousness of the allegation, the steps taken to verify it, the urgency of publication, whether the claimant was offered a right of reply, and the nature of the source.

The paper trail for this defence is therefore editorial rather than evidentiary. What you need to demonstrate is a responsible editorial process, not merely the truth of what you published. A right-of-reply email, documented verification steps, and a record of the editorial decision-making process all contribute to satisfying the "reasonably believed" test. Consulting the pre-publication defamation risk checklist before publication is itself evidence of a responsible process.

Five Mistakes Journalists Make That Undermine a Valid Defence

Even when a story would support a strong defence, these errors create avoidable exposure. First, failing to keep contemporaneous notes — reconstructed records are weaker than records made at the time. Second, mixing opinion into factual passages without clear demarcation, muddying the defence available for each. Third, not sending a right-of-reply request before publication, which weakens the Section 4 case. Fourth, updating a published story without considering whether the defence still applies to the revised version — each edition is a fresh publication. Fifth, deleting social media posts or early drafts after receiving a complaint, which can look like concealment and undermines credibility.

Quick-Reference Checklist Before Publication

Before any story carrying defamatory potential goes live, run through five questions. Can you prove the factual claims substantially true, and do your records support that proof? If the piece includes opinion, have you made the factual basis visible to the reader? Have you sent a right-of-reply request and documented the response or non-response? Is the subject matter one of genuine public interest, and can you articulate why? Have you applied independent editorial judgment, or are you relying uncritically on a single source?

A yes to all five does not guarantee immunity, but it positions your defence as strongly as the facts allow. A no to any one of them is a problem to address before publication, not after.