The borough’s police cadets had the unenviable task of inviting rush-hour commuters and office party-goers to take breathalyser tests as part of an anti drink-driving campaign on Thursday.

The young volunteers headed for Canary Wharf underground station, having also visited Mile End station the previous evening to advise the public about drink-driving limits.

They are trying to get across the message that those enjoying a post-work pint or two could still be over the limit when they get off the tube and into their car.

Reece Buckley, 17, of Augusta Street, Poplar, was surprisingly successful in getting those dashing for their train to take the test.

He said: “It’s been a bit of a mix. Some people are not interested and some people can be rude to you, but most tend to like what we’re doing.”

The simple breath test returns a pass, warning or fail verdict.

Cadets gave a leaflet to those in the warning category recommending that they not go onto drive because the alcohol levels in their blood could still be rising.

The limit is 35 milligrams in 100 millilitres of breath.

The group’s supervisor, PC Steve Austin of Bow police station, said: “People don’t always understand the limits.

“We had one guy who failed the test even though he’d had only one pint.”

Ewan Cameron, 16, a pupil at Sir John Cass’s Foundation School in Stepney Way, was never likely to fail the test but he was impressed by the work the cadets were doing.

He said: “We get to see the police out in the community and that is a good thing.”

A series of public safety operations have seen cadets handing out beer mats reading ‘Go home with Des tonight’ – Des being a friend who acts as the designated non-drinking driver - and Cabwise leaflets promoting the use of licensed mini-cabs.

Matt Gorman, 25, of Lyal Road, Mile End, who works for the Financial Services Authority in Canary Wharf admitted that the problem of drink-driving can get worse at Christmas.

He said: “A lot of the public campaigns have been good though and have made a difference.”