People who currently possess zombie-style knives and machetes are being urged to hand them in to police ahead of a ban coming into force next month.

From 24 September, the weapons will be banned under legislation passed by the Conservatives while they were still in power.

However, people in England and Wales have from 26 August to 23 September to surrender these items to police stations and claim compensation.

Policing minister Dame Diana Johnson said the ban was the first step in the government’s plan to halve knife crime in a decade and would be followed by efforts to outlaw ninja swords.

Participants in the surrender scheme have been asked to get in touch with their designated police station for advice on how to package up the weapons and bring them in safely.

Surrender bins will also be available for anyone who wants to remain anonymous.

Those who give up their weapons freely during that time period will not be arrested or face prosecution, the government said.

Zombie-style knives and machetes are defined as weapons with blades over eight inches (20cm) in length that normally have a serrated cutting edge.

They were first added to the government’s list of prohibited offensive weapons in 2016 but police have struggled to deal with knives designed specifically to get around the definition given that year.

A loophole meaning the weapons could be kept and sold if they did not have images depicting violence on their handles will be closed when the Offensive Weapons Act comes into effect next month.

According to the government, anyone found with zombie-style knives and machetes following the ban will face jail time.

“There is no legitimate need for a weapon of this kind to be in our homes or on our streets,” Dame Diana said.

“That is why we will continue to make sure the tightest restrictions are in place to limit the availability of these lethal weapons.”