In January the Chinese ­government released Liu Zhihua, one of the last ­known prisoners sentenced for “hooliganism” committed during the 1989 protests that centred on Beijing’s Tiananmen Square.

Mr Liu was 24 years old when he helped organise a strike at the factory where he worked in Mao Zedong’s home town, in the province of Hunan. The strike at the state-owned enterprise of more than 10,000 workers was in protest at the violent suppression of the pro-­democracy demonstrations.