London (CNN) An increase in online abuse directed at British Duchesses Kate and Meghan has prompted one of the UK's leading celebrity magazines to launch a campaign calling for people to change how they post online.

Meghan, Duchess of Sussex, and Catherine, Duchess of Cambridge, are frequently the subjects of abusive comments, often made against one duchess by supporters of the other, according to the royal editor of UK magazine Hello!.

The rise in abuse directed at the women comes after months of reports in British tabloid newspapers that claim they are locked in a long-running feud.

"There's a wider narrative in the media pitting them against each other, and unfortunately people are piling in and taking sides," Emily Nash, Royal Editor at Hello!, told CNN.

"It seems to me to be particularly sexist," Nash said of much of the abuse. "You have people comparing them in a way that doesn't really happen with men -- 'she's walking funny, or her heels are too high, or her legs are too skinny.'"

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