Scotland’s new hate crime law could damage public trust in police, senior officers have warned ahead of it coming into force on Monday.

Rob Hay, president of the Association of Scottish Police Superintendents (ASPS), warned of a surge of reports of hate crimes, driven by people wishing to score points against their opponents on social media.

He said police officers would be caught in the middle, with those accused of hate crimes feeling “aggrieved” if their details are kept by police, even if there is no prosecution.

Similarly, he said public trust in the force could be damaged among those lodging complaints of hate crimes if officers concluded the legal threshold for a prosecution had not been reached.

The ASPS previously warned that an “activist fringe” would seek to “weaponise” the legislation. Police Scotland has promised to investigate every complaint.

Mr Hay also said a deluge of complaints would make it harder for the over-stretched force to “focus on those crimes and offences that cause the most harm and represent the highest risk to public safety.”

Humza Yousaf oversaw the passage of the legislation at Holyrood in 2021 when he was Justice Secretary in Nicola Sturgeon’s government. However, it will not come into force until Monday as Police Scotland said it needed time for training.

The Hate and Public Order (Scotland) Act creates a criminal offence for threatening or abusive behaviour that “stirs up hatred”, expanding on a similar offence based on racist abuse that has been on the statute book for decades.

Offences are considered “aggravated”, meaning they could lead to stiffer sentences, if they involve prejudice based on age, disability, race, religion, sexual orientation or transgender identity.

However, concerns have been expressed that the legislation’s definition of a hate crime is too ambiguous, potentially leading to a “chilling” effect on freedom of speech and a torrent of vexatious complaints being made to police.

In particular, JK Rowling’s allies have suggested that trans activists have her “in their sights”. The author has regularly argued that trans women are not women and last week vowed to continue “calling a man a man” after this “ludicrous law” comes into force.

Mr Hay said: “Our concern is that could impact through a huge uplift, potentially, in reports – some of those potentially made in good faith but perhaps not meeting the threshold of the legislation.

“Or potentially in cases where people are trying to actually actively use the legislation to score points against people who sit on the other side of a particularly controversial debate.

“Sitting within the middle of all that will be a police officer, who will have to make a judgment on whether the threshold is met for the legislation, and whether any of the protections afforded in law can be applied.”

Noting that the subject of complaints may also be unhappy with the police response, he concluded: “So there are two ways potentially that we could damage trust and confidence in the police – around whether the police response meets with expectations, and whether have the police exceeded themselves in involving themselves in non-criminal matters.”

Challenged over the ASPS’s concerns, a Green minister in Mr Yousaf’s government told BBC Radio Scotland’s Sunday Show that police already have to judge whether the threshold for criminality has been reached under existing laws in cases involving verbal abuse.

Patrick Harvie, the Active Travel minister, said: “There are people out there wildly misrepresenting what is in the hate crime legislation, what it will mean and for the most part they are trying to drag it into a kind of culture war space.

“Some of the people on the Right in particular use phrases like free speech that only means freedom to be abusive and vile and unpleasant and prejudiced.”

Mr Harvie attacked “absurd, spurious comments from Conservatives” and claimed he had received “direct threats of violence” as a result.

But Joanna Cherry, a senior SNP MP and ally of Rowling, accused him of “rubbishing” legitimate concerns.

She tweeted: “It’s time politicians & commentators stopped ducking these issues & insulting feminist activists who have been campaigning for women’s rights for years. They should address our concerns properly rather than smearing us as ‘right-wing’.”

The Edinburgh South West MP warned that “there are bad actors who will seek to weaponise aspects of the new Hate Crime Act against gender-critical women.”

All cases to be investigated

A Scottish Government spokesman said: “The Hate Crime Act will help to tackle the harm caused by hatred and prejudice and provide greater protections for victims and communities. The right to freedom of expression is built into the legislation.

“The laws have a high threshold for proving offences of stirring up hatred and the supporting materials explain how the thresholds of the offences are assessed. Police Scotland has given assurances that those targeted by hate crime will be treated with dignity and respect and that the circumstances they report will be fully investigated.

“We have worked with partners, including Police Scotland, to ensure effective implementation of the legislation and the timetable for commencement has allowed for the delivery of a robust package of training and guidance for police officers.

“Training of police officers is an operational matter to Police Scotland, with whom we will continue to work closely and the Chief Constable has said police officers are being trained to apply the law in a ‘measured way, using their discretion and their common sense’.”