Fell is on leave until his notice expires. He has been at TfL for three years.
‘There is nothing sinister about my leaving and it is unrelated to Ryan,’ Fell said.
‘I oversaw some great campaigns, including the congestion charge. My last two campaigns have just come to end so it makes sense to go now,’ he added.
Fell said he was leaving to undertake consultancy work. ‘I always had a good relationship with [transport commissioner] Bob Kiley and Ryan,’ he added.
Ryan is understood to have left as a result of a breakdown of relations with Kiley (PRWeek, 9 July).