There is one extremely serious aspect which overshadows this whole thread. Of all the opinions expressed both for and against having skymarshals on UK flights, none has been either considered or discussed before taking this very major step.
The simple fact is that it has been commanded by the US government and so Tony Blair has meekly and obediently complied. No consideration has been given to possible pitfalls or the objections raised by BALPA and UK pilots in general. Just who runs the UK? Evidently not anyone that we got to vote for.