England World Cup winner Ben Cohen has walked out on Northampton after being overlooked for the club captaincy.
Cohen was born in Northampton and joined the club when he was 17
The 28-year-old winger has not attended training since losing out to Bruce Reihana for the role last Wednesday.
"Ben came to see me and said he was unhappy about not being appointed captain. He said 'that's it, I'm off'," said Saints chairman Keith Barwell.
Cohen's spokesman said: "Ben hoped their differences could be dealt with amicably and privately."
Barwell said he was "bitterly disappointed" with Cohen, adding: "He has been a brilliant servant to the club for more than 11 years but no man is bigger than the club."
Cohen has previously been linked with a move to Leicester, but Northampton insist they will not terminate his contract, which still has one season left.
Ben saw the challenge of the captaincy as one he would have relished for the club he has played for his whole career and cares for deeply
"Ben's contract with the club runs until the end of the coming season and he is not able to play for any other club in the meantime," said Northampton director of rugby Jim Mallinder.
Barwell has given his full backing to Mallinder's decision to stick with New Zealander Reihana, who led the side last year, as captain.
"It is the director of rugby's responsibility to appoint the captain and I support Jim's choice of Bruce Reihana wholeheartedly - his decision must be final," said Barwell.
Cohen, who made his Saints debut in 1996 and won the Heineken Cup with them in 2000, has met with Barwell and Mallinder in recent days and both requested he return to training.
But the 2003 World Cup winner was conspicuous by his absence from the Northampton squad that faced Samoa in a friendly last Sunday and has not been seen this week.
His spokesman said: "Given the Saints' relegation to Division One, Ben was to keen to take on more responsibility and saw the challenge of the captaincy as one he would have relished for the club he has played for his whole career and cares for deeply."
Cohen, who is currently in the middle of a testimonial year, joined Northampton when he was 17.
He has made 270 appearances for the Saints since his debut in 1996 and won 57 caps for England, scoring 31 tries.
The powerful 6ft 4in winger withdrew from England's World Cup training squad in May in order to spend more time with his wife, Abby, who is expecting twins.