Jan 22, 2012 5:45 AM GMT
Secretary for the National Federation of Atheist, Humanist and Secular Student Societies, Michael Paynter,said: 'Robbie stepped aside because he signed up as president to organise events and run a student society.
'He did not appreciate the stress he would be under when dealing with a controversy like this, so he wanted to make way for someone else.'
The Ahmadiyya Muslim Youth Association's protest against the photo has been backed by UCL's Union.
A UCL Union statement said: 'The atheist society has agreed they will take more consideration when drawing up publicity for future events.