UPDATE 2.05PM: Muster staff have been left "totally shocked" by today's decision to make executive director David Gibson's resignation effective immediately.
Mr Gibson's resignation was originally set to be effective on March 31.
Festival director Melinda Wells said the decision, which has also resulted in the resignation of other Muster staff, is borne of irreconcilable differences over the festival's future direction.
"We are united in that belief as the working office team and paid staff of the Muster," Mrs Wells said.
MORE UPDATES AS YESTERDAY'S SHOCK NEWS UNFOLDED
Mar 20, 5pm: Muster's future in hands of Apex and board
Mar 20, 4pm: Muster resignations - big job ahead - says board
Mar 20, 3.30pm: Muster board meeting hastened Gibson's departure
Mar 20, 11.45am: BREAKING: Future of the Muster uncertain after mass resignation
"The three of us as current employees could not see ourselves in these roles making the Muster successful this year with the current board.
"We've stated that right from the beginning to now."
In a statement, Janell Cox said the current situation had become unworkable for staff.
"It has become clear over the past few weeks that due to circumstances beyond our control the actions of the board now mean that there is no longer an alignment in direction between the Muster staff and the board, therefore we all believe that it is in the best interests of the Muster that we resign to provide adequate time to recruit new staff to deliver an event that aligns with the vision of the board," she said.
"We all remain united in the decision to leave the Gympie Muster Ltd and we saw this as the only way forward for ourselves and the future of the Gympie Muster."
Ms Cox and Mrs Wells have both resigned, although Ms Cox said her decision had been made in mid-January, with notice given at that time, while Mrs Wells tendered hers last Wednesday.
In leaving, they said they had regrets over the situation, and hoped to see the Muster continue to be a success in the future.
EARLIER: 11.45am: MASS resignations from Gympie Muster staff have left the future of the iconic music event up in the air.
According to sources, executive director David Gibson and the entire staff of the Muster - except for one member - have tendered their resignations, citing an inability to work with the board as the reason for their departure.
While Mr Gibson was expected to finish up on March 31, having already given notice, the decision was made in a meeting with the board he would step down effective today.
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In a statement, Mr Gibson said he had made the difficult decision to move on after two years with the Muster.
"It has become clear over the past few weeks that due to circumstances beyond our control, the actions of the board now mean there is no longer an alignment in the direction between the Muster executive director and the board.
"Therefore, we all believe it is in the best interests of the Muster that I resign to provide adequate time to recruit new staff to deliver an event that aligns with the vision of the board.
"I want to thank the community and the hundreds of volunteers for their professionalism and support for the Muster during my time at the role and I hope to see you out at the event as a patron in future years."
More information as the story develops.