It’s only right that our Home Secretary should think very carefully and weigh up all the facts before making an informed decision on the use of water cannon in London.

Now that she’s delaying the decision, she should go further and conduct a comprehensive review of all the tools available for policing public order. Sound cannon is one example of a cheaper and more mobile alternative.

In emergency situations, such as the 2011 riots, where order breaks down, missiles are being thrown and shops looted by mobs, the police would benefit from having sound cannon.

Costing as little as £18k, they are 25 times cheaper than water cannon, they look like satellite dishes and emit a targeted, high pitched alarm tone in short bursts. They also have a loud-hailer mode which can be used to broadcast verbal instructions and warnings from a long distance. They’ve been deployed in cities such as New York, Chicago and Barcelona. Indeed, given that they were available in London for the 2012 Olympics, why don’t the police have them already?

Richard Tracey

GLA Conservatives Assembly Member for Merton and Wandsworth