London - Britain's head athletics coach Peter Eriksson said on Wednesday he was stepping down just seven months after he took the job so that he can return to Canada to be with his family.
Eriksson's departure plunges the sport in Britain into uncertainty just before the start of the domestic outdoor season.
He was appointed to succeed outspoken Dutchman Charles van Commenee in the wake of the 2012 London Olympics, having coached Britain's Paralympic team to a third-place finish in the overall medals table.
In his first competition as head coach, Eriksson led Britain to a strong showing at the European Indoor Championships in March with an eight-medal haul, including four gold.
"Words cannot describe how disappointed I am to take this step," Eriksson said.
"There is no bigger job in athletics anywhere in the world. At present I have no plans, but accept that if I am to take any other job in sport it will be a step down."
Eriksson said the generous financial support that British athletics receives from the National Lottery "means it is every coach's dream to hold this position".
"However no job is more important than family and children, and personal circumstances mean that mine need me to be back in Canada," he added.
Eriksson was born in Sweden but moved to Canada in 1987. His wife and four daughters have remained in Canada during his time in Britain.
British Athletics Performance Director Neil Black could not hide his disappointment at Eriksson's decision.
"This is a big disappointment but it could not have been foreseen six months ago, and Peter has been open with us on the personal challenges he faces," Black said.
Eriksson's softer management style was widely welcomed by the athletes after the abrasive Van Commenee, who was often openly critical of their training and preparations.
He will continue in his position until the end of June, leading the British team to the European Team Championships in Gateshead on June 22-23.
Black will take over the head coach duties for the remainder of the summer, including the World Championships in Moscow on August 10-18.