As Moazzam Begg sat on a wall in Parliament Square, holding a yellow rose and a white sign reading “I oppose genocide, I support Palestine Action” in neat black lettering, you could be forgiven for thinking this was a spontaneous moment of quiet defiance.

But in fact, the arrest of the former Guantanamo Bay detainee on Saturday was the culmination of days of careful planning meant to send a message – that protesters were able to overwhelm the police as they sought to challenge the Government’s decision to brand Palestine Action a terror organisation.

With 365 arrests and counting as the protest wound up, it was not clear that Mr Begg’s side had succeeded in that aim.

Mr Begg remained silent during his arrest. But comments from others in the crowd shattered the apparent dignity of the moment and revealed a deep hostility towards the police and the state of Israel.

As police led Mr Begg into a waiting van, one protester shouted: “Pigs! Get your hands off Moazzam! Get your hands off Moazzam, you f------ pigs!”