A charity fundraiser encouraging primary school students to wear a dress has raised $75,000 for girls’ education in the developing world after the Australian Conservatives senator Cory Bernardi claimed it was an example of “gender morphing”.

Craigburn primary school’s Do It in a Dress appeal aimed to raise just $900 through gold coin donations but has blitzed its target after Bernardi complained on Twitter it was an “absurd” example of “gender morphing”.

One school in SA now has 'wear a dress day'. This gender morphing is really getting absurd #auspolhttps://t.co/399EoSQxYz — Cory Bernardi (@corybernardi) September 20, 2017

The Do It in a Dress appeal will allow children to wear dresses on the last day of third term or to wear casual clothes if students “don’t feel comfortable wearing a dress”.

The school’s appeal website said children took part in the campaign because “we don’t think its fair that some girls in the world don’t have access to an education and a positive future”.

The charity states that $300 provides an education for one girl in Africa and the school’s total so far of more than $75,000 amounts to 250 girls being educated.

Responding to Bernardi’s tweet the gay comedian and LGBTI rights advocate Josh Thomas said the event was raising money for charity and had “nothing to do with ‘gender morphing’”.

He accused Bernardi of “bullying” children “for trying to help underprivileged girls”.

These kids are being bullied by Cory for trying to help underprivileged girls. The site it linked to has been taken down. It appears he won. — Josh Thomas 🌈 (@JoshThomas87) September 20, 2017

Thomas pledged to donate $1,000 to support the cause and then increased his contribution to $2,000, which was matched by his agency, Token Artists.



Thanks to @tokenartists (my representation) for matching my $2k donation we are now past 12X their fundraising goal. https://t.co/aDcziX8qVZ https://t.co/ZMPbLnzCaF — Josh Thomas 🌈 (@JoshThomas87) September 20, 2017

On the school’s donation page, Carolyn Dalton, who donated $55, said: “Such great work kids. I only heard of this fundraising due to Cory Bernardi’s criticisms of you and your school.

“Please don’t listen to him – you kids are doing a wonderful thing. Please accept this contribution instead.”

On ABC Radio on Thursday Bernardi defended his stance, arguing that the charity event had gone beyond the “time-honoured tradition” of casual clothes days by encouraging boys to wear a gendered item of clothing.

He said the children had been politicised and “indoctrinated” and encouraging boys or allowing male teachers to wear dresses was “inappropriate”.

The South Australian education minister, Susan Close, responded that it was “disgraceful” that Bernardi had politicised “an innocent and well-meaning idea”.

At a doorstop on Thursday education minister, Simon Birmingham, said that if children “want to have a bit of fun” on the last day of term to raise money for a good cause “that is something that we should celebrate and not condemn”.

Asked about Bernardi’s motivations, he replied: “I think some of those running the no campaign at present will say and do anything to try to encourage people to vote no, that it’s about creating a scare campaign when there is only one simple question Australians are answering, and that is should same-sex couples be allowed to marry.”

Claims that marriage equality will impact the gender education of children have been central to the no case in the same-sex marriage postal survey campaign, with the first Coalition for Marriage ad claiming schools will allow boys to wear dresses and compel students to roleplay same-sex relationships.

In response to the ad, the executive director of the Equality Campaign, Tiernan Brady, said the no campaign “know that Australians believe everyone should have the same opportunity to marry, so they are deliberately resorting to misleading people”.

“Sadly, the Australian people will now hear a daily dose of red herrings and dishonesty served up by a huge bucket of cash.”

On Thursday the Business Council of Australia chief executive, Jennifer Westacott, slapped down claims from anti-marriage equality advocates that children raised by same-sex couples are worse off, labelling them “deeply offensive and wrong”.