The reason that Mark Field attacked the lady who had just passed by him was that she wore a sash clearly identifying her as a climate change protestor. She had entered with the other guests, already wearing her sash, and making no effort at concealment. Field knew exactly that she was a climate change protestor when he attacked her: it is why he attacked her. Had she just passed by him without that sash, he would not have attacked her.

There is zero history in the UK of personal violence or terrorist attack by climate change protestors and nobody could claim they had a reasonable fear that a climate change protestor was carrying a weapon – something which has simply never happened. I could equally rationally grab Mark Field by the throat any time I saw him, and claim he might have been carrying a concealed weapon because he is a Tory MP. His excuse is a complete and utter nonsense, a post hoc effort at justification.

He only had a genuine fear of her carrying a weapon if he is suffering from a serious psychological derangement, and one dangerous to the public.

Unlike Mark Field, I happen to have led a life involving real danger, and had guns pointed at my head in both Uzbekistan and Liberia, whilst in the service of the UK. But in my sixty years I have never once raised my hand in anger to a woman. Field’s unprovoked attack was cowardly and ungentlemanly in the extreme (and I really do not care if you find my attitude outdated or not).

It is worth observing that there was not a gentleman at this gathering of Britain’s bankers and upper classes. Nobody stood up to try to assist the peaceful woman who had been grabbed by the neck. Sickeningly, they applauded Field on his return. I find the extraordinary tirade of Tory defence on twitter this morning says a great deal about the kind of party it has become.

One point that appears to have been missed in media comment, is that it seems to me extremely likely that the woman had an invitation or ticket for the event. She was dressed in evening wear as the other guests, but was not attempting to infiltrate or gatecrash or she would not have worn the sash. The most probable reason for someone to follow the dress code but identify themselves with a protest sash is that they were a legitimate guest wishing to make a point.

It is essential to our society that Mark Field is immediately arrested and charged with assault. If Tories are allowed simply to assault people lest they make a speech that Tories disagree with, society has turned a corner to somewhere very dark indeed.