The accusation of traitor is a big one indeed.
Ed Hussain has written a book which I have read, in it he betrays private conversations he had with people. In Islam it is forbidden to betray peoples trusts.
He attacks the concept of Khilafah as an expansionist state. Question is how was Khilafah established and by whom and how did it spread?
He seems to have a problem with this issue.
If there are problems amongst Muslims and Islamic groups, lets resolve it among ourselves and not by writing books attacking each other and being used as a pawn by the enemies of Islam.
Do some research to find out which non-Muslims are happy with these guys.
As for Majid Nawaz and everybody else, as and when they do anything against Islam, then we as Muslims have a duty to account them, even if it means calling them what they are " Western Agents".