The ad to boycott Mumsnet, which ran ahead of Mother’s Day, stated: “Say it with hate this Mother’s Day” and included a picture of a young boy with negative words such as “pig, rioter and wife beater”.
It advised advertisers to suspend advertising on the Mumsnet site “until founder Justine Roberts adopts a zero tolerance policy on gender hatred”.
The ad attracted a number of complaints that challenged the claims made against Mumsnet and whether they were misleading and could be substantiated.
A number of further complaints challenged whether the derogatory words within the ad itself were offensive.
Fathers4Justice said that Mumsnet is responsible for the content hosted on its site and that the ad was a legitimate way to raise the matter.
The ad watchdog ruled that it was misleading for Fathers4Justice to imply that Mumsnet made or endorsed these comments within its own editorial, and that the ad breached advertising regulations.
Complaints against the content of the ad being offensive were not upheld by the watchdog.