SNP MP Joanna Cherry has hit out at Nicola Sturgeon’s suggestion that equal marriage laws for gay people may not pass through Scotland’s parliament today due to the “toxic” level of debate.

Cherry, a prominent figure in the SNP and vocal critic of the party's approach to gender identity, said the claims were “nonsense”.

The disagreement comes after the former first minister appeared at an event organised by the School of Social and Political Science at the University of Edinburgh to mark 25 years since the reconvening of the Scottish Parliament.

Speaking alongside former deputy first minister Jim Wallace, who is now a LibDem peer, Sturgeon said the culture in politics could be “downright unpleasant. It's downright toxic."

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She went on: "I was the minister that took through minimum unit pricing. I don't think that would get through and onto the statute book today.

“I'm not even convinced equal marriage would – certainly not without a much more toxic debate – get there today.

"So a lot of it comes back to, how do we fix that underlying problem of we've just lost our way in how to debate things rationally and properly."

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However, Cherry – a vocal critic of the gender reform bill, which would have removed the need for a medical diagnosis before someone can legally change gender – dismissed Sturgeon’s claims.

Responding on social media, the SNP MP wrote: “Anyone with any longevity in the gay rights movement or the fight for equality can properly judge the gains made and the changes in our society and knows this is nonsense.”

“Self ID on the other hand is not about equality it’s about special privileges (for men),” Cherry added.

Same-sex marriage was made legal in Scotland in early 2014.

The SNPs’ new leadership under John Swinney has given assurances that there will be no rolling back of rights amid concerns following the appointment of Kate Forbes as Deputy First Minister.

Previously, Forbes’s socially conservative views, including saying she would have voted against gay marriage, have sparked controversy.