Locked up for more than four years and ailing, the message of Hong Kong's pro-democracy media mogul Jimmy Lai would only become stronger if he died in prison, his son says. Speaking outside the gates of London's Downing Street, Sebastien Lai says he also hopes that US President Donald Trump's upcoming state visit to the UK will provide a good opportunity for the two countries to "work together" for his father's freedom, something he says both governments say is a "priority case". IMAGES AND SOUNDBITES