Less than three per cent of shopkeepers in Harrow and Brent failed to pass age-restricted sales tests last year.

Statistics from Brent and Harrow Trading Standards for 2019/20 showed the vast majority of those tested were successful in dealing with minors looking to buy products such as tobacco, alcohol and knives.

In Brent, three traders out of 65 (4.6 per cent) failed to follow the correct procedures when confronted by under 18s looking to buy alcohol.

Council officers noted one was given a simple caution while the other two received warning letters.

A further 38 were tested on tobacco, knives and e-cigarettes, with all requesting ID and refusing sales where appropriate.

In neighbouring Harrow, just one shopkeeper out of 19 tested slipped up when it came to tobacco sales.

This represented 5.6 per cent of tests in this section, but, with 53 traders passing across all products, just 1.9 per cent in the borough overall.

In 2018/19, Brent’s failure rate was similar to last year at around 3 per cent, however, Harrow’s, at almost one in ten (9.6 per cent) was much higher.

Officers said there is a wider push across the region to reduce knife crime by re-evaluating knives sales in shops.

Anu Prashar, senior service manager at Brent and Harrow Trading Standards, explained that they have been asking traders to “move where their knives are kept, question who they are selling knives to, and whether they should be selling knives in the first place”.

They have also clamped down on shops selling knock-off tobacco, including through using sniffer dogs and looking in unusual places such as “microwaves and crisp packet boxes”.