The stand-off culminated in a group of councillors calling on Bell, then 24, to resign, while a ratepayer started a petition calling for Parry to resign as chief executive.
Earlier on Tuesday a council spokesperson said “the council was committed to ensuring a smooth transition from outgoing chief executive Stephen Parry to a new chief executive, and having the right interim chief executive was critical to achieving this”.
Capil will leave the council next month to take up another role, the spokesperson said.
In his resignation letter, Capil thanked Parry for his support.
“I came to the council to work with you, and I have enjoyed the chance to do that,” Capil said.
“The senior leadership team and staff are fantastic and again I have valued the opportunity to be part of a very special staff at the council.
“A fantastic team and a fantastic work environment from an operational perspective.”
Capil was a central figure during the breakdown in Parry and Bell’s relationship.
He was the senior staff member at a meeting behind closed doors where the relationship was discussed.
A vote of no confidence in Bell was brought up during the meeting, though it did not reach a vote.