Roy Disney, nephew of Walt Disney and vice-chairman of the entertainment giant, has resigned and called on chairman Michael Eisner to do the same.
Roy Disney says the firm has lost its soul
Mr Disney attacked Mr Eisner's leadership in a letter released ahead of a Disney board meeting this week.
"You and I have had serious differences of opinion about the... style of management in the company," he wrote.
He said the Walt Disney company had "lost its focus, its creative energy and its heritage" under Mr Eisner.
"You have driven a wedge between me and those I work with... I find this intolerable", Mr Disney said.
Mr Disney has worked for the company since
1967, and led the expansion of Disney's animation department since 1984.
He has been angered what he sees as Mr Eisner's strategic blunders.
In particular, Disney has been hit by problems at the television network ABC, which it acquired in the mid-1990s.
And its theme park division, which Mr Disney said had been run over-cautiously by Mr Eisner, has suffered falling attendances.
"You have tried to build parks 'on the cheap' and they show it and attendance figures reflect it," Mr Disney said in his letter.
He bemoaned what he characterised as the "rapacious, soul-less" corporate culture introduced by Mr Eisner, under which long-term public trust and affection had been sacrificed for the sake of short-term financial gain.
Stanley Gold, a fellow director and an ally of Mr Disney, also announced his resignation.