The Government has been warning for weeks about the threat posed by terrorists and the discovery of deadly ricin in a London flat served to prove the point.

But before we all become too scared to step outside our homes, let's examine the facts.

It's true that terrorists can get hold of ricin fairly easily and that there is no known vaccine or antidote.

But scaremongers who claim it could be used to kill large numbers of people at once are wide of the mark.

Ricin has been used in the past as a means of assassinating individuals and has been highly effective.

But while it is undoubtedly lethal, researchers at the University of Sussex are confident it is not an easy chemical to turn into a weapon of mass destruction.

There is a danger from terrorists using chemical or other weapons. We should all be on our guard.

But it's important not to get things out of proportion. The cell discovered by police was small and the amount of poison discovered was minute.

No one should discount the ability of some fanatics to use anthrax, as happened last year in the USA, or sarin gas, which killed passengers in the Tokyo underground.

The terrorist's greatest weapon is fear.

And as we teeter towards war in these uncertain times, that is being stoked as readily at home as abroad.