Staff at the Centre for Alternative Technology (CAT) signed a vote of no-confidence letter to senior management after a shock redundancies announcement.
The letter described the Powys learning institution as a "sick organisation" with management that are "defensive, aggressive, secretive and disrespectful".
The letter was written after the visitors centre closed in November with immediate effect, with management blaming the closure on financial difficulties and a "drop in footfall".
As a result of the closure, 14 members of staff were made redundant, leaving 85 staff and 10 volunteers. The letter accuses senior management of handling the closure without consulting staff.
It goes on to accuse management of announcing the redundancies poorly, whereby multiple staff found out they were at risk via social media or from members of the public "on their way to work".
It also describes a pay review earlier in the year as being dealt with "disastrously".
Staff and volunteers signed the anonymous letter calling for "drastic action" to save CAT by listening to those who keep the centre's "wheel's in motion".
The letter addressed to CAT trustees and allegedly signed by up to 55 staff and volunteers reads: "CAT is and has been a sick organisation for several years.
"We believe this sickness, brought on by fundamentally poor management and decision making has led to our current position.
"This letter acknowledges that it may be too late to save jobs and the visitor centre and that drastic action is needed to save the organisation of CAT as a whole.
"However the narrative that this is only due to external factors and not the responsibility of those that hold responsibility is angering and disrespectful to all of us who work above and beyond to keep the wheels of CAT in motion."
The official statement regarding the visitors closure and staff redundancies states "staff wellbeing is of utmost priority" and that the institution was providing "specialist support to staff during this difficult time".
It blames the visitor's centre closure on "rising running costs, reduced visitor numbers and funding delays".
Cambrian News understands that CAT is still waiting for the £24m Levelling Up money promised to CAT to create a "world-class visitor experience".
The letter continues: "You may believe CAT is a well-functioning organisation with opportunity for cross-department working and for two-way conversation with management. The reality is far from this.
"CAT has a highly hierarchical model of management which is largely underpinned by defensive, aggressive, secretive, disrespectful and non-collaborative working methods.
"This is only highlighted in the way the recent announcements were made to staff, whereby those facing redundancy were given 15 minutes notice to attend a meeting, in which one of the co-CEOs simply read out the public notice regarding closure and redundancies and refused to take any questions.
"Some staff that are facing redundancy heard the news via social media and the general public. This has understandably caused significant feelings of anxiety, anger, and discontent.
"This follows on from a disastrous process around pay and progression which has done more damage than good within the organisation.
"CAT is an ecology of interrelated and dependent components. The decision to close the visitor centre has been taken without consultation and will have significant unintended consequences. Not least for the social and cultural value that this brings to all our operations."
Since the closure the number 34 bus route which services the centre and nearby towns of Corris and Ceinws has been put up for review.
Last year CAT changed its pay structure with a "disastrous" consultation process, according to anonymous members of staff, in which low-wage staff came out "poorly".
An anonymous member of staff said: "The pay review has left a lot of people feeling hurt and angry, now this closure is another blow.
"The pay at CAT is minimum wage for most and those were the people in the firing line." The 50-year-old organisation had previously been admired for being cooperatively run and consensus-based, where at one point almost all staff were on the same wage.
The learning centre switched to a hierarchical structure with wide-ranging salaries over 10 years ago.
The letter signs off: "Finally, staff work incredibly hard at CAT, keeping their head down and working through the difficulties day to day because we all have a shared belief in the narrative of what CAT is and where it came from, why the world needs CAT and what CAT can be in the future.
"Because of this, unhealthy practices can breed more easily within the organisation, because the greater good is bigger than any one person or department's pain.
"If CAT is to survive, you need to listen to us, you need to hear our voice and not the curated voice that comes from the management. We are in crisis.
"You need to get in touch with us all and take drastic action, we all want to help to save these jobs, to save the ecosystems and organisation of CAT that we all love.
"This letter has no one author, it is the product of the people you employ."
The letter was attached to a poll voting "no" or "low confidence with serious concerns" for Co-CEO's Eileen Kinsman, Paul Booth, or the senior management team.
According to a member of staff there was no satisfactory reply from senior management other than a small exchange of emails with trustees.
The staff member said: "The vote of no confidence has been ignored and further eroded trust in both senior management, CEOs and trustees.
"The redundancies are from the lower paid staff, there are senior managers and two CEOs on big paychecks and they aren’t even dropping some hours to help avoid redundancies of their fellow colleagues.
"There’s been no mention in the press or social media of the mismanagement of resources or the severely poor leadership when discussing the cause of these financial issues but those are huge factors that are viewed by most of the staff body as fundamental in this situation."
A CAT student who wanted to remain anonymous said: "The closure of the visitors centre is heartbreaking.
"I have so much love for CAT, the work it does, and the people who work here. It's just such a shame the management team is completely disconnected from the daily lives of the people who work here.
"It affected services available to me as a student such as the convenience of having the cafe there. It made me less likely to use the site. The mood has shifted dramatically on site.
"People who have spent decades working here and pouring their heart and soul into making this place special have left voluntarily because of the ethos the management team are practicing."
A spokesperson for CAT said: “We can confirm a letter was received by CAT’s Trustees in November - shortly after we announced, with a heavy heart, the closure of the Visitor Centre to day visitors.
"The letter was promptly responded to - including an offer to meet with the sender/s. The wellbeing and opinions of our staff and volunteers are of utmost priority, and we welcome the opportunity to meet with the sender/s and anyone else who wishes to speak to us.
“Additionally, we are already creating more opportunities to increase communication between staff, senior management and our Board of Trustees.
"These include hosting regular drop-in sessions, increasing the frequency of staff meetings and introducing new working groups - bolstering our mission to continue creating and sharing practical solutions to tackle the climate and nature emergency, both now and in the future.”