If its recommendations are followed, the independent review of Prevent conducted by William Shawcross will mark one of the most important and welcome milestones in counter-extremism policy.

The operative word, however, is ‘if’ — because the review itself highlights some of the barriers to effective action that have bedevilled this area for many years.

It is not simply that the fear of being labelled as Islamophobic has too often hampered vital action with regard to extremist Islamic groups; it is that the accusation is deliberately used by organisations which are themselves part of the problem to neuter criticism, and that some of those involved in the supposed implementation of counter-terrorism policy are themselves dangerously close to support for organisations such as Hamas and Hezbollah.

The Shawcross review is a devastating indictment of the various institutional failures. In one example, officials even excused support “by those in senior political or community roles” for terrorist groups which are dedicated to the the murder of Jews.

The report highlights the full extent of the malaise, with some organisations that have received Government funding to fight extremism themselves promoting antisemitism and antisemitic figures. As the report puts it: “There is no reason why those who support Hamas should be treated any differently to those who support Islamic State, National Action, or other proscribed organisations.”

The Home Secretary, Suella Braverman, has certainly said the right things in response, pledging to “rid Prevent of any cultural timidity so that it meets every threat head on and does more to identify and challenge non-violent extremism.”

But although this is the first thoroughgoing review of Prevent, we have nonetheless been here many times before, with senior politicians promising change but the status quo remaining. Ms Braverman is correct that the fundamental problem is cultural. For the lessons from the review to be learned, Whitehall itself will need to change its attitude.