Police in Western Australia are calling for the power to be able to “nudge” cars off the road during pursuits without facing any legal repercussions if it results in a fatal crash.

The West Australian police union has demanded the Barnett government introduce the legislation after a fatal crash in Perth on Saturday in which a teenager in a white Ford Falcon that had been chased by police allegedly crashed with a red Nissan Pulsar, killing a couple in their 60s.

Police say they began to chase the Falcon when the driver allegedly refused to pull over and then aborted the chase when it began to drive erratically.

The crash happened a short time later at the intersection of Warwick Road and Ballantine Road in Warwick, in Perth’s northern suburbs. A 66-year-old man and a 60-year-old woman were killed; their 25-year-old son, who was driving, was seriously injured.

A 16-year-old boy who was allegedly driving the Ford Falcon was charged with two counts of manslaughter and a string of dangerous driving charges.

The union’s president, George Tilbury, said the crash could have been avoided if police had been able to take “proactive action”, including a controversial “PIT manoeuvre” or precision immobilisation technique, which police are not permitted to use in any jurisdiction in Australia.

“A PIT manoeuvre is generally when police are pursuing a vehicle they move alongside the rear quarter panel of the vehicle, they give that vehicle a nudge, it makes it spin out, lose control and then police can apprehend the offenders,” Tilbury told reporters in Perth on Thursday.

He said giving police the authority to use that manoeuvre, and other moves such as pinning-in cars or using roadblocks, could save “innocent” lives but acknowledged it could risk the life of the person being chased.

“The priority here is to protect innocent members of the community and police officers who are doing their jobs,” he said. “If offenders decide to flee from police they suffer the consequences.”

Tilbury said some police had already used the prohibited techniques, including during the high-profile capture of a 38-year-old man who escaped from Fremantle police lockup last week. The man was caught the next day following an hour-long police chase which ended, he said, when police “nudged the vehicle,” and caused it to lose control.

No one was injured in that incident but, if they had been, police could be liable.

“There is no protection for police officers at this present time if they take proactive action to force vehicles off the road,” Tilbury said. “So that is a decision that they make but they’re putting themselves at risk if something was to go wrong.”

The acting WA police commissioner, Gary Dreibergs, said the actions proposed by the union were too risky.

“The underlying principle of everything relative to pursuits nationally is the principal of safety first, and that’s the safety of police officers, safety for the community – that’s just the No 1 thing in our mind at all times,” Dreibergs told 6PR on Wednesday.

“[Hypothetically] if they ram a vehicle and ... it doesn’t work, the offending vehicle rolls, there’s young people in that vehicle, regardless of what they’ve been doing, and they die.”

The push by the police union comes a week after a WA coroner handed down her findings on the 2012 death of Sharon Ann D’Ercole, who died when her car was hit by a police vehicle that was chasing another car. The coroner ruled that, because the police officer driving the car had been acquitted of a dangerous driving causing death in 2013, she had to find D’Ercole’s death was an accident.

Tilbury noted Dreibergs’ concern but said he would put it to the police minister, “because at the end of the day if community sentiment is there to support this action politicians will act and we will see something introduced”.

The Barnett government in 2012 introduced mandatory minimum penalties of six months’ jail for people found guilty of reckless driving while seeking to escape pursuit by police and dangerous driving causing bodily harm while seeking to escape pursuit by police. If the pursuit results death or serious injury the mandatory minimum sentence is 12 months’ jail.

Labor’s police spokeswoman, Michelle Roberts, said some of the options proposed by the union were “quite radical” but “shouldn’t just be written off out of hand”.

The number of incidents classified as a police pursuit in WA have tripled over the past five years from 322 in 2010 to 1,029 in 2015.

The current policy requires police get permission from someone ranked an Inspector or higher to start a pursuit and does not allow police to continue chasing a vehicle past certain speeds or if would pose a risk to other drivers on the road. Instead the car is tracked from the air.

Dreibergs told ABC radio on Thursday that a new helicopter, equipped with surveillance cameras, would provide more support for officers on the ground.

The police minister, Liza Harvey, has been contacted for comment.