LAST November I was walking beside the river on London's South Bank when I noticed two armed policemen on patrol.

One was carrying a two-handed combat weapon. I considered this to be offensive and went over to speak to the officers. It turned out that they were protecting government property in the area.

The second policeman had a hand gun, a taser stun weapon, a CS spray and a baton. The two-handed weapon is a Heckler and Koch MP5 Carbine, set to fire single shots. I wrote to Boris Johnson in his role as chairman of the Metropolitan Police Authority, but the letter never reached him and was treated as a normal complaint against police behaviour. After more letters I eventually received a detailed explanation from Kit Malthouse, the deputy mayor for policing.

He countered my arguments that the patrols increased the danger to the public. The patrols of the Government Secure Zone (GSZ) are just one part of the overall strategy to protect this area and the wider London communities. He appreciated that the sight of police carrying firearms may be alarming to some. But not, I would contend, to the terrorists or suicide bombers whom they are intended to deter.

Instead it tells them where their enemy is!

I copied my correspondence to Barry Gardiner MP, who secured a legalistic reply from the Home Office minister.

Barry Gardiner did not express a view, unlike his predecessor Dr Rhodes Boyson, who wrote to me in 1986 that he was alarmed whenever he saw armed police.

On that occasion I had complained about the deployment of blatently armed police at Heathrow Airport. The nub of my argument against deploying overtly armed police is that they cannot achieve their intended aim. Because there is an inbuilt traditional view that arming the police equals better protection, nobody in authority has tried to visualise the actual circumstances in which a Heckler and Koch Carbine would be used. Just think about it?

I defy anyone to show how an occasional patrol by a pair of armed policemen can do anything to protect property or persons in a public area.

The open display of arms by police on the South Bank, or any other neutral place of resort, is an outrage against civil society.

DAVID PEARSON Windermere Avenue

Wembley