A Golden Dawn supporter raises his hand in a Nazi-style salute during a rally in Athens in 2014 [Yannis Kolesidis/AP Photo]

A Golden Dawn supporter raises his hand in a Nazi-style salute during a rally in Athens in 2014 [Yannis Kolesidis/AP Photo]

On Saturday, tens of thousands of anti-immigration protesters are expected to march through the streets of London under the banner “Unite the Kingdom”.

Leading it will be Stephen Yaxley-Lennon, known as Tommy Robinson, the oft-described combative Luton-born, anti-Islam activist who has long rejected the label “far right”.…