Celtic have confirmed that Peter Lawwell will step down from the board at the end of the year with the non-executive chairman stating that "abuse and threats from some sources have increased and are now intolerable."
The announcement comes hours before the side's league clash against Dundee United with Lawwell to step down on 31 December and be replaced by current non-executive director Brian Wilson.
The club are experiencing difficulties on and off the pitch with November's AGM was abandoned after hostility between directors and fans.
The meeting was temporarily adjourned less than five minutes in amid chants of "sack the board".
And it was ultimately closed early as shareholders reacted to a statement from director Ross Desmond, son of the club's biggest shareholder Dermot, which accused a section of fans of being "bullies".
On the field, recently-appointed Wilfried Nancy became the first Celtic manager to lose his first three games after their League Cup final loss to St Mirren on Sunday.
LawwEll became the Scottish club’s chief executive in 2003 and served for 18 years before moving into the chairman’s role.
"It is with sadness that I announce my decision to stand down as Chairman of Celtic FC," a statement from Lawwell on the club website read.
"I believe that my 18 years as Chief Executive and three years as Chairman at the Club have shown my ability to meet and overcome challenges on many fronts, but abuse and threats from some sources have increased and are now intolerable.
"They have dismayed and alarmed my family. At this stage in my life, I don’t need this. I cannot accept this and so I leave the Club I have loved all my life.
"The motivations and aims of these detractors can be investigated by others. I prefer to look back on my career at Celtic with deep gratitude and satisfaction.
"My time at the Club has brought joy to someone whose memories as a Celtic fan include standing as a schoolboy on the terraces as the European Cup was paraded at Celtic Park on that magical night in 1967.
"I have subsequently watched some great European nights at Paradise and am proud that the Club has played group-stage football in all but two of the last 21 years while also enjoying domestic dominance.
"I also take great pleasure in the continuing and ever more substantial impact of Celtic FC Foundation. The Club’s Foundation impacts so many lives in the Celtic Family and far beyond. We are more than a football club and the Foundation is the most obvious evidence of this truth.
"Our achievements were all made possible by a dedicated workforce and a fervent support binding together. I am deeply proud and privileged to have been part of that.
"My life at the Club has included dramatic ups and downs in football but they have also given me the experience, drive and desire which I will take on to my next project, whatever and wherever that may be.
"My thanks go to my many colleagues over the years who have supported me, and I am grateful to the coaches and players who delivered this era of remarkable and historic success."
