Prime Minister Rishi Sunak has said people should not be criminalised “for stating simple facts on biology”, as he backed author JK Rowling in her criticism of new Scottish hate crime laws.

The Harry Potter author, who has become a fierce critic of the Scottish Government’s stance on transgender rights, has been one of the highest profile critics of the legislation.

The Hate Crime and Public Order (Scotland) Act came into effect on Monday, consolidating existing hate crime legislation and creating a new offence of stirring up hatred against protected characteristics.

However, women have not been given protection under the law, with the Scottish Government instead promising to bring forward legislation to tackle misogyny.

But with the new Act giving protection to transgender people, Rowling – who does not believe people can change their gender – insisted: “Freedom of speech and belief are at an end in Scotland if the accurate description of biological sex is deemed criminal.”

In a statement given to The Daily Telegraph, Mr Sunak promised that his party will “always protect” free speech.

“People should not be criminalised for stating simple facts on biology,” he said.

“We believe in free speech in this country, and Conservatives will always protect it.”

In a social media post criticising the new laws, Rowling insisted that the “legislation is wide open to abuse by activists who wish to silence those of us speaking out about the dangers of eliminating women’s and girls’ single-sex spaces”.

She argued: “It is impossible to accurately describe or tackle the reality of violence and sexual violence committed against women and girls, or address the current assault on women’s and girls’ rights, unless we are allowed to call a man a man.”

The children’s author also appeared to challenge police to arrest her if her social media posts break the new laws.

“I’m currently out of the country, but if what I’ve written here qualifies as an offence under the terms of the new act, I look forward to being arrested when I return to the birthplace of the Scottish Enlightenment,” she said.

However, Humza Yousaf declared that he is “very proud” of the new laws, saying they will help protect against a “rising tide” of hatred.

The Scottish First Minister also insisted he is “very confident in Police Scotland’s ability in order to implement this legislation in the way it should”.

It comes despite the force confirming more than an third of its officers have not yet completed an online training course in the new laws – with Deputy Chief Constable Alan Speirs saying that 10,000 of the force’s 16,000 plus officers have done so.

However Mr Yousaf said Chief Constable Jo Farrell had “made it very clear the appropriate training is absolutely being provided”.

She said recently that the new laws will be applied “in a measured way”, promising there will be “close scrutiny” of how the legislation is enforced and what reports are received.

The Scottish Government’s Health Secretary Neil Gray was asked about Rowling’s comments when he appeared on the BBC’s Good Morning Scotland programme on Tuesday.

He said he would not comment on “particular postings” but the Hate Crime Act “merely extends” protections around stirring up racial hatred to other groups and there are protections for freedom of expression in the legislation.

Stirring-up offences require people to have used “threatening or abusive language”, Mr Gray said.

He said: “There’s been quite a bit of misinformation around what this legislation actually does, the protections that it extends.

“I hope that means that we can tackle the hatred that has been permeating across these isles for far too long.”