Kevin Keegan has ended several days of speculation over his future at Newcastle United by confirming his resignation as the club's manager.
The 57-year-old had been locked in talks with the St James' Park hierarchy, but those discussions have failed to persuade Keegan to stay on.
A statement from the two-time Magpies boss read: "I've been working desperately hard to find a way forward with the directors, but sadly that has not proved possible.
"It's my opinion that a manager must have the right to manage and that clubs should not impose upon any manager any player that he does not want.
"It remains my fervent wish to see Newcastle United do well in the future and I feel incredibly sorry for the players, staff and most importantly the supporters.
"I have been left with no choice other than to leave."
An additional statement from the League Managers' Association read: "The letter which Kevin received today from managing director Derek Llambias has failed to resolve the matters in issue between him and the club and accordingly he feels he has no alternative other than to resign."
Keegan only returned to Tyneside in January, following the sacking of Sam Allardyce, having previously spent five years in charge at the club between 1992 and 1997.
He was reported to have been unhappy at the club's transfer deadline dealings, especially with the exit of winger James Milner to Aston Villa.