As many as six in 10 retailers in some UK areas were found to be breaking the law and selling knives to children as young as 14, whilst Tesco, Amazon and Argos were also caught out by a BBC Watchdog.

A test purchase operation by North Yorkshire County Council revealed that six out of 10 retailers – three bricks-and-mortar businesses and five online retailers - sold knives to a 16-year-old. Meanwhile, a company director has been ordered to pay more than £5,500 after a store employee illegally sold a pack of 13 knives to a 14-year-old girl, following a test purchase prosecution by Croydon Council.

The employee who sold the knives was given a four-month prison sentence suspended for 12 months, ordered to pay £315 in costs and given a community order. It was revealed police had previously given a verbal warning to the shop for selling a two-piece cutter set to two 13-year-olds in school uniform.

In another case study, it was revealed that three shops were investigated after selling knives to a 15-year-old boy and a 16-year-old girl following a test purchase operation carried out across nine retailers by Stoke-on-Trent City Council trading standards. The children were able to buy a Stanley knife and two utility knives without being asked for identification. Two of the retailers received written warnings and one remains under investigation.

Most shocking of all was that, despite having signed up to a voluntary code in 2018, Tesco and Argos were found to be selling knives to 16-year-olds without making proper ID checks, according to a recent BBC investigation.

A 16-year-old actress, sent by BBC Watchdog, was able to buy a kitchen knife that it is illegal to sell to someone under 18 in Tesco and Argos.

Amazon also broke its own delivery rules by handing over four knives ordered by the programme to the girl and leaving another one in a location for her to collect.

In total, the teenager visited five different branches of Wilko, Asda, TK Maxx, Tesco and Argos. She was sold a knife in three of the five Tesco stores that she visited, while one Argos store sold her a knife with no ID being checked.

Four of the knives ordered from Amazon were delivered into her hands and one was left in a bin, rather than following the company's policy and refusing to hand them over to the teenager.

It was confirmed that no branches of Wilko, Asda and TK Maxx sold a knife to the 16-year-old.

The firms have responded to the findings, saying they will investigate the claims. In 2018, all of the retailers announced they had signed up to a voluntary code, committing to check the ID of anyone they suspect of being under either 21 or 25 before selling or delivering a knife to them.

The worrying findings come as latest official figures show a 59 per cent rise in knife crime in England and Wales in the past five years.

The Local Government Association (LGA) believes the dedicated Home Office Prosecutions Fund – set up as part of the Serious Violence Strategy – does not provide enough help to council trading standards teams to enforce breaches of knife law sales, by in-store and online retailers in the longer term.

The £1million funding, split equally over two years, was given to 11 councils for in-store test purchase operations in 2018/19, as well as funding one council to run a national online test purchase operation.

The LGA says the success of the test purchasing operations last year means most of the funding allocated for 2019/20 will have to be used to prosecute those businesses already caught making illegal knife sales. As a result, there will be only enough funding left to support further in-store test purchases by six councils, with no further online enforcement planned.

With trading standards budgets and staffing having been cut by around half since 2010, as a result of cuts to council funding, the LGA is calling for more funding to be allocated to the Prosecutions Fund to support enforcement activity in 2019/20 and for the Fund to be extended beyond 2020 as part of the Spending Review.

Councils’ trading standards teams are also concerned that they don’t have the necessary resources to enforce the requirements of the new Offensive Weapons Bill, which is likely to become law later this year.

The Bill will make it a criminal offence for knives and dangerous corrosives sold online to be delivered to anyone aged under 18 at a residential address, and for dangerous corrosive products, such as acids, to be sold to anyone under the age of 18.

Councils will have new responsibilities for undertaking underage test purchase operations at the point of delivery for online knife sales and for enforcing restrictions on sales of acids and other corrosives. Councils also face the cost of providing advice and training for businesses about the new legal requirements.

Cllr Simon Blackburn, chair of the LGA’s Safer and Stronger Communities board, said: “Rising knife crime is causing horrendous destruction and grief in our communities and councils are uncovering some shocking cases of illegal knife sales which risk fuelling this tragic epidemic.

“The retail supply of knives and acids needs to be managed robustly across all sales points, and retailers must ask for proof of age if they suspect the buyer is under 25.

“The Prosecutions Fund announced in the Serious Violence Strategy has helped some councils prosecute retailers for blatant breaches of knife sale laws.

“However, given the knife crime epidemic, the significant cuts to trading standards budgets and the extra enforcement activity that will be needed when the Offensive Weapons Bill becomes law, this Fund needs urgent further investment and extending to many more councils to tackle illegal knife sales and protect people from harm.”