Supermarkets will have to think twice before bringing a complaint against a rival’s adverts after the Advertising Standards Authority introduced new rules to stem the flow of tit-for-tat complaints.

From this month, a rival will no longer be able to lodge a complaint unless it can prove it has tried to resolve the issue with the competitor.

The watchdog is struggling to deal with the volume of complaints it is currently receiving, especially after its remit was extended this year to cover online. It wants to stop companies using the tit-for-tat tactic to create free negative publicity for rivals. An ASA spokesman said the big grocery retailers had been particularly active with the tactic this year.

The ASA has been inundated with complaints from the supermarkets about rivals’ ads since Asda launched its original Price Guarantee in April 2010. The watchdog upheld complaints from Tesco, Sainsbury’s and Morrisons that Asda’s initial advertising was misleading.

However earlier this year it threw out subsequent complaints regarding Asda’s 10% Price Guarantee. At the time the ASA said the economic climate meant retailers were engaging in much more comparative advertising.