Boris Johnson came back to the frontline of politics this morning to warn of the huge risk of a second wave of coronavirus infection if the UK lockdown is lifted too soon.Speaking on the step of Downing Street a refreshed looking Prime Minister said it was too early to ease the lockdown restrictions in the fight against the virus .With his trademark hair ruffled and voice firm the Prime Minister looked recovered as he attempted to level with the country about the long road out of lockdown.Johnson, who was hospitalised by the virus three weeks ago, said from his personal experience that Covid-19 was “an unexpected and invisible mugger” but that the lockdown efforts of the public made this “the moment when we have begun together to wrestle it