Morrisons has said it plans to follow Tesco and complain about new adverts from rival grocer Asda which claim to be 10% cheaper.

A spokesman for Morrisons told Bloomberg: “Morrisons will be making further challenges to the ASA on the adverts.”

He said: “We will be focusing particularly on the individual details of the ads going forward, challenging specific claims that they make.”

The ASA ruled on Wednesday that earlier adverts from Asda on its price guarantee were not clear in their current form. It said the ads did not make clear what was included in the guarantee. The ruling followed complaints from Tesco and Morrisons that the ads included non-grocery items such as books and football-related merchandise, which could not be compared in its price guarantee.

Since the beginning of the year, Asda has stepped up its advertising promising to be 10% cheaper. This is now the point that Tesco and Morrisons have complained about.