Joey Grima has stepped down as head coach on London Broncos.
"It would not be fair on staff, our club, the players and supporters if I could not plan and lead our club to my full capacity," he said.
Assistant coach Andrew Henderson has been put in interim charge, starting with Sunday's game against Workington.
Grima, a former assistant coach of Parramatta, joined the Broncos as number two to Rea just over two years ago.
He was unable to keep them in Super League after becoming boss and they have lost two out of three Championship matches this season.