Friday has been in charge of the England Sevens since 2004

"Mike resigned a couple of weeks ago and his resignation is in no way related to Andy Robinson's departure," a RFU spokeswoman told BBC Sport.

Friday, 34, took over from predecessor Joe Lydon in April 2004.

Friday is currently with the England Sevens squad in Dubai preparing for the Emirates Airline Dubai Sevens.

The tournament starts on Friday.

Friday said: "I have enjoyed working with the England Sevens players and management since 2001 when I first joined Joe Lydon as assistant coach, and have also enjoyed my time as a National Academy coach.

"I will miss the team spirit that the Sevens squad enjoys, as well as the pride in watching the youngsters progress through their careers, but I will continue to follow their progress with interest."

Under Friday, England enjoyed back-to-back wins in the Emirates Airline Dubai Sevens and a record four successive wins in Hong Kong.

England also won the silver medal at the Commonwealth Games in March 2006, the first time England had won a Commonwealth medal for rugby, and finished second in the IRB Sevens series last year.

RFU elite rugby director Rob Andrew said: "I have known Mike for a number of years both as a player and most recently in his role with the Sevens squad and am sorry that he is leaving the RFU.

"Mike has a real talent for developing young players and the track record of the Sevens programme over the past few years of developing young England players speaks volumes on his ability as a coach."