Jim,
"Sympathisers" is a meaningless accusation - does that mean they are potential terrorists or just that they are pissed off with the abuse and racism that has been rained down on them for decades

Abedi is a good example.
Members of the Muslim community reported him speaking in support of terrorists and saying it was OK to be a suicide bomber.
That is what I meant by "sympathiser" and it does not get you onto the watch list of 3000, you are just one of the 20 000.

There have ben no declarations of open support from any section of the Muslim community - on the contrary, these attacts have been condemned unreservedly by them

No-one disputes that Jim.

That condemnation merits support, not quotes of meaningless and unresearched figures which cast suspicion over all British Muslims

What meaningless and unresearched figures?
The figures I gave are from the police and security services of all the suspects they are aware of.