If you google "CPS terrorism" or "CPS jihadi" you'll find that the CPS is heavily involved in cases involving terrorist-related matters. In fact, they have a special division, the Special Crime and Counter Terrorism Division, headed by one Jenny Hopkins. Whilst it's certain that the Home Office and Foreign Office liaise closely with the CPS, any dark murmurings and knowing winks about leaning-ons, etc, by the government had better be supported by some solid evidence in m'humble. In due process in this country, the duel tenets of evidence and public interest must be maintained, and seen to be maintained, whether in terrorism-related matters or in anything else.

If that was a response to my comment about this case being outside the general scope of the CPS you will find that most (if not all) of the links which can be found from your suggested searches relate to online, or physical, actions taken in this country.