London Mayor Sadiq Khan announced his plan on Monday to ban body-shaming ads on the city’s transportation network starting next month.

Khan, who was elected in May, said the ads targeted in the ban promote “unrealistic expectations” surrounding women’s bodies. “As the father of two teenage girls, I am extremely concerned about this kind of advertising which can demean people, particularly women, and make them ashamed of their bodies,” he said in a statement. “It is high time it came to an end.”

The mayor of the United Kingdom’s capital also said he is working with transportation authority Transport for London (TfL) to establish a group to monitor and enforce the new rules.

“Advertising on our network is unlike TV, online and print media. Our customers cannot simply switch off or turn a page if an advertisement offends or upsets them and we have a duty to ensure the copy we carry reflects that unique environment,” TfL Commercial Development Director Graeme Craig said in a statement.

Khan had promised to take action on body-shaming ads during his campaign after a specific “Beach body ready” campaign last April led to protests and an online petition with more than 70,000 signatures, The Guardian reports.

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