The UK's advertising watchdog has asked dairy firm Muller to pull a campaign following a complaint from rival Yoplait.

The Advertising Standards Authority (ASA) ruled against adverts for Muller's Little Stars range, which, it said, misled consumers after implying the ingredients in the product were naturally produced.

The ruling, announced today (25 March), follows an intervention from Yoplait, which questioned whether the "100% natural ingredients" claim was fair and accurate.

The ASA also upheld a second complaint from Yoplait, which argued that Muller's use of two taglines in the campaign misleadingly implied all the ingredients in the Little Starts range were completely natural.

Muller had claimed that the taglines - "A helping hand from Mother Nature" and "It's almost like getting a helping hand from Mother Nature" - were "hyperbole". The company also claimed it was legitimate to state that Little Stars comprised "100% natural ingredients".

However, the ASA said the use of the taglines in the ads, as well as the "100% natural ingredients claim" implied that the ingredients in Little Stars "were less processed and closer to nature than they were".

A third compliant from Yoplait over the number of ingredients Muller promoted as being in the Little Stars range was waved away.

However, the ASA ruled that Muller could not show the TV and print ads again in their current form.

Muller officials could not be reached for immediate comment.