Parking attendants, care workers, nurses and teachers were assaulted more than 40,000 times last year for simply doing their jobs, according to the public sector union Unison.

The union says there is particular concern over levels of violence and threats directed at staff in services for children in care and those working with children with significant learning difficulties.

Meanwhile the mistreatment of traffic wardens has also caused concern with the union warning that some parking attendants have been driven at by irate drivers looking to injure or intimidate them while in one instance a driver wrestled the ticket machine from a worker and attempted to hit him with it.

The union says last year saw public sector workers assaulted in the course of their work more than 40,000 times for the third successive year, as it published its most recent survey of violence in the public services.

Assaults on public sector workers can be prompted by frustration on the part of members of the public unhappy at austerity-driven cuts or delays, it said.

The union is calling for the Scottish Government to do more to "end the aggro" after councils and NHS boards and other public services responding to the survey confirmed they had logged 40,568 violent incidents last year between them.

The figures represent a small drop on the 2016 and 2017 surveys – there were 42,241 violent incidents reported last year and 41,166 in the 2016 survey – but Unison says the number incidents has more than doubled since it first instituted an annual survey of violence against public sector workers in 2006.

The results of the 2018 Violence and Work survey were published at the union’s Health and Safety seminar in Stirling. Scott Donohoe, UNISON Health and Safety committee chair, said:

"We believe these figures are the tip of the iceberg. There is a huge issue of underreporting."

Key sectors are missing from the survey. The Scottish Fire and Rescue Service did not respond  and hereas last year 30 of Scotland's councils reported figures, this year's survey includes responses from only 23.

Unison says Police Scotland should also be more open about the issue. Having failed to respond in 2015 and 2016, last year it provided a figure for assaults on police officers, but not a full report covering all employees including police staff in detail. This year itprovided a figure for officers and staff but no detailed breakdown of this.

Meanwhile 14 of Scotland's 17 higher education providers included in the survey reported just five incidents between them. "Unison is very sceptical. One of our reps says he knows of five incidents in his own institution alone," Mr Donohoe said.

"These public bodies should be reporting back about what they are doing to tackle threats of violence and aggression against their workers", he added.

He said abuse directed at public sector workers ranged from being sworn at, spat at, punched or assaulted.

Incidents included one teacher who had been pushed over by a young person with severe learning difficulties, injuring their leg and forcing them to take time off work, he said.

"Residential child care is a big issue as well, with workers reporting physical violence threats and psychological abuse. Vulnerable kids need to be looked after but councils also have to accept that there is a duty of care to staff."

This years survey found that assaults on local government workers account for around half of the total, at 20,208, while health boards reported a total of 18,225 assaults on NHS workers. A further 2125 incidents were identified in returns from other organisations including quangos, universities and colleges and culture and leisure trusts.

Mr Donohoe told the conference violence against public service workers was on a "massive scale" and should not be tolerated. He called for all employers responsible for delivering public services to adopt guidelines on violence in the workplace produced by the Scottish Centre for Healthy Working Lives and to sign up to the UNISON Violence at Work Charter which aims to support staff who often face violence when providing essential and undervalued caring services.

He also said specific legal protections for workers in the emergency services should be there for all workers. “We support the extension of legislation covering violence at work to cover all workers engaged in delivering public services – and not just the emergency services," he said.

"The Scottish Government must move to address this issue. We now need action by employers and stronger legislation, regulation and oversight by government to end the aggro. It really isn’t ‘part of the job’.”

Norman Provan, Royal College of Nurses Scotland Associate Director, said: "Nursing teams are already under pressure due to staff shortages and increasing demands; they should not have to put up with verbal or physical assaults from those they are caring for or their families.

"All health boards have a duty of care to protect their staff from attack. They are expected to have policies in place to deal with these distressing situations and must always listen to their staff. They should also make clear to patients and their families that that they have a zero tolerance approach to any harassment or violence and that they will report all incidents to the police and seek a conviction if appropriate.”

A Scottish Government spokesman said: “Attacks against our NHS staff are despicable and the perpetrators must be dealt with in the strongest possible terms.

“No-one should be the victim of abuse or violence while at work. We continue to encourage all NHS organisations to support criminal proceedings against anyone who assaults our staff.

“The Emergency Workers Act includes a penalty of up to 12 months imprisonment, a £10,000 fine, or both. In 2008 this government extended the act to include GPs and doctors, nurses and midwives working in the community.”