Jess Tye, investigations manager at the Advertising Standards Authority, told the BBC that gender stereotypes in advertising could cause “real-world harms”.
“Ads that specifically contrast male and female stereotypes need to be handled with care,” she said.
“It’s about thinking about what the cumulative effect of those gender stereotypes might be.”
Mondelez UK argued that the ad showed a positive image of men with a responsible and active role in childcare in modern society. It said it chose to feature a pair of fathers to avoid a stereotype of new mothers being responsible for children.
The ASA said the ad had a light-hearted and comical intent, but portrayed the men as “somewhat hapless and inattentive, which resulted in them being unable to care for the children effectively”.
It said the ad “relied on the stereotype that men were unable to care for children as well as women, and implied that the fathers had failed to look after the children properly because of their gender”.
Volkswagen UK said that its ad made no suggestion that childcare was solely associated with women, and the fact that the woman in its advertisement was calm and reading could be seen as going against the stereotypical depiction of harassed or anxious parents in advertising.
The ASA said the ad presented gender stereotypes “in a way that was likely to cause harm and therefore breached the code.”
It said by juxtaposing images of men “in extraordinary environments and carrying out adventurous activities” with women who appeared “passive or engaged in a stereotypical care-giving role”, the ad had suggested that stereotypical male and female roles were exclusively associated with one gender.
The ASA introduced its ban two months ago because it found some portrayals could play a part in “limiting people’s potential”.
The new rules cover both broadcast and non-broadcast adverts, including online and social media.