In the RCP, Cliff was a supporter of the majority tendency of that party around Jock Haston and Ted Grant. Therefore, he supported the perspectives of the RCP at the end of the Second World War which placed the small party in opposition to the new leadership of the Fourth International around Ernest Mandel, then known as Germain, and Michel Raptis, better known as Pablo, which was backed by the American Socialist Workers' Party. In this capacity he wrote "All That Glitters is not Gold" in which he discussed his view that, contrary to the opinion of the International Secretariat of the Fourth International, there was not going to be a major slump.