Businesses will find it harder to protect brands from the negative effects of comparative advertising – in which one company promotes its products by drawing comparisons with rivals – after a landmark ruling this week, lawyers have warned.

Wedlake Bell, a London law firm, said that a combined ruling in two cases at the Court of Appeal confirms that the Human Rights Act’s (HRA) provisions for safeguarding freedom of expression should apply when a Court considers a request for an injunction to block a contentious advert.

Comparative advertising – for instance, when one internet service provider claims to offer a faster, more reliable service than named competitors –- is an increasingly popular marketing tool.

Although the UK courts have always taken a relatively hard line towards businesses crying foul over competitors’ claims, Wedlake Bell said that this week’s ruling will make it harder still to convince judges to ban adverts.

“By confirming that the freedom of expression aspects of the HRA should apply to advertising, the Court of Appeal has raised the burden of proof that a company needs to show before a Court will block a rival advert,” Mike Gardner, a partner at Wedlake Bell, said.

“Whereas previously the claimant only needed to show that they had an arguable case before a Court would consider an injunction, under the provisions of the HRA, they know need to show their case is ‘likely’ to succeed at trial – a harder thing to demonstrate - before an injunction will be granted.”

An injunction prohibits publication of the offending advert until the issues can be considered at a later hearing. Since hearings can take several months to come before the courts, an interim injunction is a crucial means through which businesses can secure an early victory against their competitors.

Since such injunctions will become harder to win, Mr Gardner predicts that comparative advertisers will become more aggressive and take more risks in the kind of claims they make about the difference between their own and rivals’ goods.

Mr Gardner said: “The Court of Appeal judgment shows how the Human Rights Act can have influence beyond the areas where one would expect it to operate.

“Although the majority of claims involving so-called ‘freedom of expression’ involve individuals or the media, commercial comparative advertising is now accepted as being a form of expression like any other.

The Human Rights angle is clearly a factor that advertisers and their competitors cannot overlook from now on.”

The case was Boehringer Ingelheim & Ors v Vetplus and concerned claims about the relative strengths of the two companies’ dog supplements.

The Institute of Practitioners in Advertising, an advertising trade body, was not immediately available for comment.

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