Stephen Nolan with Mark Serwotka

Stephen Nolan speaks to Mark Serwotka, General Secretary of the UK's largest civil service union - the Public and Commercial Services Union. He leads around a quarter of a million civil servants and central government workers. Since spring 2010 Mark has experienced serious heart problems. He's now being kept alive by a machine which pumps blood around his body powered on batteries that he carries around in a bumbag.