[2] The group was banned at the start of World War II, and many of its established leaders left politics.
With his brother, Murray maintained an underground newspaper, and this gave them the impetus to found the Revolutionary Workers Party (RWP).
[3] Murray became editor of its newspaper, Labour Challenge, then briefly co-editor of a Quebec edition of the French Trotskyist paper, La Verité.
In response to this, Murray theorised that World War III was imminent, and that given the weakness of the RWP, it was necessary to immediately enter the Cooperative Commonwealth Federation (CCF).
[4] He eventually politically reconciled with his brother and was a regular speaker at forums held by the Socialist League in the 1970s.