17:32 BREAKING NEWS: Ed Miliband has given an interview, which has just been shown on the BBC. He insisted that Johnson has stepped down for personal reasons and not political differences.
"Alan Johnson was the right man for the job. He has had to stand down for personal reasons, nothing to do with this job"
He was asked whether the appointment of Balls signalled a change in direction for economic policy – as Nick Watt says below, Balls had a more hawkish line on the deficit. But Miliband insisted that his views were "similar". He added:
"I am looking forward to working with him, in the direction that Alan has set out"