Boris Johnson has posted a rare message on Chinese social media urging Russia not to invade Ukraine. The post on China’s largest social media platform, Weibo , was a Mandarin translation of the message he wrote on Twitter earlier in the week: We are on an edge of a precipice but there is still time for President Putin to step back. We’re urging everybody to engage in dialogue and for the Russian government to avoid what would be a disastrous mistake for Russia. — Boris Johnson (@BorisJohnson) February 14, 2022 Since Mr Johnson became Prime Minister, the No 10 Weibo…