Jeremy Corbyn has led well-wishers after it emerged the Second World War veteran and political activist Harry Leslie Smith is seriously ill in hospital.The 95-year-old was “not in a good way” and had been taken into A&E, his son, John, said.Mr Smith was understood to have fallen ill in Canada, where he was visiting his son, the Daily Mirror reported.Born in Barnsley, South Yorkshire, Mr Smith served with the RAF in Germany and in recent years campaigned on behalf of the NHS.On Wednesday morning, #IStandWithHarry was trending on Twitter as messages of support flooded in. Mr Corbyn said: “Very sorry to hear this. Please pass on my best to Harry. We need him to get well soon as the National Health Service, and our movement, needs him.”Karl Turner, Shadow transport minister, added: “Very much hope Harry makes a full recovery. We need him.”A tweet from his son posted on Harryslaststand on Wednesday morning said: “It is after midnight here but I think he will see the morning and then we will go from there.”Earlier, he said: “After being examined by the icu doctor, Harry exclaims, ‘I can assure you, I am not ready to die because I have too much work to do’.” This is Harry Leslie Smith’s son, John. Harry is in A & E and not in a good way. He asked me to inform you in case things don’t work out. I will keep you posted.— Harry Leslie Smith (@Harryslaststand) November 20, 2018 Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily  Front Page newsletter and new  audio briefings.