On Friday, Harriet Harman declared her support for the No More Page 3 campaign. Not long afterwards, the following tweet appeared on No More Page 3's twitter feed: "would respect her for addressing endemic muslim paedophilia, but no, nice soft target"

This piqued my interest, not only because of the bizarre idea that 'paedophilia' is either exclusively Muslim or indeed endemic, but because it is a response that has been often thrown at the campaign and its supporters. These commenters are under the impression that feminists should campaign "on some REAL issues rather than this pathetic shit." They think that the campaign is an easy way for us to "preen" and insidiously present ourselves as "jolly brave and radical", when the reality is that we are afraid to tackle the real sexist issues - which they have helpfully informed us reside almost exclusively within the UK's Muslim community.

I'm sure these commenters are trying to be helpful to the feminist cause; unfortunately, they are somewhat misguided.

Firstly, and hopefully reassuringly for them, people are capable of focusing on more than one thing at a time; as an example of this phenomenon we need only look to our MPs who seem to manage to focus on quite a few things at the same time as they run the country (in a manner of speaking). So for those concerned that Page 3 is not worthy of our time when, globally, one in three women will be abused, don't worry: we will continue to campaign against all forms of violence and oppression.

Less reassuringly for these sanguine commenters, the aggressive reactions of those who object to the removal of page 3 (and it's always object to the removal, rather than positively support), demonstrate that this is far from a "nice, soft target". They also demonstrate that sexism is not an issue that can be conveniently filed away under "things we have already dealt with".

The most common tactic deployed by those who disagree with the campaign is to try to undermine the position from which we object. This takes a number of forms, the most regular being to suggest that we speak from a position of "envy", "jealousy" and "insecurity". We are "bitter", "self-obsessed", "pitying" and, strangely, "vain", because we are "ugly", "flat-chested", "older", "less pert", and, almost inevitably, "lesbians". These attacks on our looks are closely followed by comments which dismiss our arguments and evidence as "nagging", "whining" and "moaning" - undermining tactics which are linked with the next most popular approach, which is to call us "immature", "pathetic", "little girls" and patronise us by addressing us as "dear".

Harriet Harman herself came in for a disturbing level of direct abuse following on from her declaration of support. These ranged from the predictable cries of jealousy ("ur just jealous some women have tits worth looking at but nobody want 2 see ur droopy spaniels ears"), to more aggressive attacks, such as "Suck my cock you fucking ginger nannying arse bandit".

While perhaps more imaginative than your average slur, this final comment employs the age-old tactic of silencing women with threats of sexual violence. And this is particularly interesting in the light of Lynn Featherstone's comments that page 3 has an effect on domestic violence, for which she was attacked by unrenowned domestic violence expert Charlotte Vere.

Vere accused Featherstone of ignoring "the real causes of domestic abuse" - rhetoric which is reminiscent of comments that accuse No More Page 3 of ignoring the "real" causes of sexism.

And Vere is being just as disingenuous.

Just because Featherstone suggested a potential link between page 3 and domestic violence, that does not mean that we need ignore all the other "causes". Furthermore, while a direct causal link is impossible to prove until we have complete transcripts of everyone's brains, charities that specialize in domestic violence, such as The Freedom Programme and End Violence Against Women (EVAW) both consider the objectification of women in the media to be a considerable contributory factor towards violence against women. They cite a number of independent investigations, one of the most compelling being a 2009 Princeton study which scanned the brains of heterosexual men looking at sexualized images of women in bikinis. The areas of their brains that lit up were those that light up when we anticipate using tools; these women were responded to as objects to be used. Small wonder then, that the American Psychological Association cites a range of studies demonstrating that when people view media that portrays women as sex objects, they become significantly more accepting of sexual harassment and interpersonal violence.

And this acceptance is borne out by comments which defend page 3 by saying that "The day women stop portraying themselves as sex objects is the day I might think of doing the same, ie never". It is borne out by assertions that the models "demean themselves". And, perhaps most disturbingly, it is borne out by the claim that the women who pose "voluntarily risk sexual assault", and therefore it is no business of ours to interfere.

The comments which suggest that Page 3 models are fair game because they post topless form part of the same culture that considers Harman fair game because she speaks up. This is a culture that views women as no more than an a tool to be used for the sexual gratification of men. And that Page 3 proclaims this message across the UK every day was starkly highlighted by today's Page 3, which featured "Hattie, 23, from Camberwell". The Sun's message to Harman, MP for Camberwell? You may be an MP, but you're still just a pair of boobs and don't you forget it. Or, to quote Andrew 'Thrasher' Mitchell, "best learn your place".

The Sun's political editor claims in a tweet that this is a "joke". And he's right, it is a joke. It's a joke that The Sun claims that Page 3 is 'a bit of harmless fun' and yet still uses it to undermine women who object. It's a joke that The Sun claims that Page 3 is 'empowering' and yet sees no problem in substituting the model's true name (Lacey Banghard) for another - because boobs are interchangeable, right? And it's, this time, a genuinely funny joke that The Sun cannot see that they have just shot themselves squarely in the foot.

With this clumsy attempt to shame and silence Harman, The Sun has joined the ranks of internet commenters who refuse to engage with the arguments of the No More Page 3 campaign. And the reason for this is the oldest in the book: they don't have an argument. Because there is no positive argument for Page 3. All there is is bullying, silencing and sexual aggression.

So yes, today's Page 3 is a joke. And the joke's on them.

Sign the No More Page 3 campaign

Follow Caroline Criado-Perez on Twitter: www.twitter.com/WeekWoman