File picture: Damir Sagolj / Reuters.

London - When you have enjoyed an evening out rather too much, getting a cab home is often a necessity.

But that may soon be harder to do as Uber has developed a method of identifying clients who may be drunk.

It spies on those using its taxi hailing app to see if they are behaving normally. If not, drivers are alerted so they can reject potentially troublesome passengers. Uber’s technology allows it to see whether customers are, for instance, typing clumsily into their smartphone - making spelling mistakes when submitting their destination or pick-up point.

According to the patent, drafted 18 months ago and published last week, the system also monitors how they are holding their phone, their walking speed and how long it takes to request a ride. This can then be matched with the user’s location and the time - near a nightclub and in the early hours, for example.

It is not known when the technology will be introduced but experts have warned it could mean vulnerable passengers are unable to get a cab home safely or find themselves charged more.

Professor Andre Spicer of Cass Business School in London told the Daily Telegraph: "This opens up the opportunity for drivers to identify drunk passengers and potentially take advantage."

Worse still, it could lead to more people trying to drive drunk.

Uber has not commented.