It was the sort of coffee shop chat I’ve heard a hundred times before but still makes me lose the will to live. I was having lunch a couple of weeks ago and two young women in their twenties were at the next table comforting their pal, who had clearly just split up with her boyfriend. All was as it should be as the tears flowed and tea and sympathy was dispensed. Then the girl who’d had her heart broken left the cafe, and the conversation took a different turn.

“I’m actually not surprised he finished with her,” confided one of the remaining women to the other. “She’s put on so much weight recently. And that dress she wore to the party was so slutty… ” A litany of other physical and personality “failings” followed. With friends like that, who needs enemies, eh?

Every woman reading this will be familiar with this sort of conversation. I’ve no doubt been the subject of similar sessions over the years, and admit shamefacedly that in the playground I took part in them, too. After all, girls are brought up to be far more judgemental of other women than they are of men, and it takes wisdom, self-knowledge and guts to resist such behaviour.

I suppose I hoped that as the patriarchal grip on women’s lives loosened over the years, which in some ways it definitely has, so too would women’s need to do the misogynists’ dirty work for them. The latest evidence suggests this has not happened. In fact, social media could be turning back the clock and making the problem even worse.

A recent study by the think tank Demos specifically monitored the use of the words “slut” and “whore” on Twitter over a three-week period, and found that 6,500 unique users had been targeted by 10,000 explicitly misogynistic tweets. Men have always used the internet to be sexually aggressive and abusive towards women, but what shocked me most about the Demos evidence is that half of the tweets they logged were directed by women towards women.

This makes the experiences of politicians such as SNP MP Tasmina Ahmed-Sheikh and her Labour counterpart Jess Phillips all the more grim and perplexing. Ms Ahmed-Sheikh, the member for Ochil and South Perthshire, spoke out in the media last week about the racist and sexist abuse she’s experienced online since her election in 2015. Much of it is explicit and far too offensive to repeat here, and all is directed with the express purpose of making Ms Ahmed-Sheikh, an articulate and accomplished woman, feel small and powerless. That is what domestic abuse and rape is about too, of course. Ms Phillips, meanwhile - another accomplished woman - received more than 600 rape threats in one night after she had the temerity to be involved in the launch of a campaign against online sexist bullying.

I don’t doubt that the majority of the rape threats against Ms Phillips were perpetrated by men, and in Ms Ahmed-Sheikh’s case, the two abusers who have been jailed for their behaviour towards her are both male. But in my view one of the most serious consequences of “women on women” sexist abuse is that it encourages men to think such language and behaviour is acceptable. Over the years I’ve heard various male colleagues and friends use the “Why is it OK for a woman to say ‘slut’ or ‘bitch’ but not me?” excuse and it makes my heart sink every single time. My answer is simple: it’s not acceptable for either men or women to use these terms, and sensible folk of both genders know better.

To be fair, I don’t think the situation is being helped by some in the feminist movement either. US model Amber Rose, for example, encourages young women to dress up in skimpy clothes and take part in “Slutwalks” in an attempt to “celebrate” and “reclaim” the word for women. Such initiatives, however, have me shaking my head in disbelief. This word is so deeply rooted in the subjugation of women and their sexuality that it is surely way beyond redemption? Why play into the hands of the misogynists, whether they be acting aggressively in the street or on social media?

Surely these young women –and indeed their older counterparts – would be better to put their energies into exposing and challenging sexism when they see it, whether that be online or in real life. And that means amongst themselves, too. How can we women expect men to stop oppressing us because of our gender, to think about the language they use and treat us with respect when we do exactly the same thing to our female relatives, friends and colleagues all the time?

With this in mind, let’s stand with Tasmina Ahmed-Sheikh and Jess Phillips. And, even more importantly, let’s stand with each other.