Jeremy Corbyn loved the march. For him it was magical. “I noticed something very different from any experience I had before. A political march that was fun, a political march that was a celebration, a political march that was music, that was optimism, that was enjoyment, that was hope”.

He would remember that 1969 May Day in Santiago for the rest of his life.

Last weekend, hundreds of thousands of people marched through London to call for a second referendum on leaving the European Union. Mr Corbyn was not there. Instead he was in Geneva, meeting Michelle Bachelet, a survivor of imprisonment and torture by the Chilean dictator General Pinochet who later became that country’s first female president. He was celebrating the 20th anniversary of