An independent inquiry reported racist, homophobic and misogynistic abuse at the site which is run by Brighton and Hove City Council.
The inquiry, which heard from 70 witnesses, also reported accounts of threats by staff to stab others, and GMB reps threatening to strike to avoid appropriate action from managers.
Other incidents reported included racist graffiti, misogyny against female managers and ‘catfishing’ gay staff on Grindr.
Aileen McColgan, who authored the report, wrote: “What should be straightforward managerial decisions on the utilisation of staff when, for example, people are off sick, escalate into morning-long events with members of staff storming off and crews going out hours late.
“This witness told me that managers have to run everything through the GMB reps to avert threats of strike, [...] and that the addition of even a single property to a round required a consultation process with the GMB reps lasting weeks.”
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The report said many of the individuals accused of these inappropriate behaviours are either GMB reps within the council or are among a group of 10 white men who were described by witnesses as having been protected by the GMB reps within the council.
The GMB said the behaviour was unacceptable, but that the people who were subject to allegations had not been allowed to respond.
The spokesperson told HR magazine: “There are also a number of areas where sweeping allegations are made on the basis of anonymous, unsupported statements that cannot be fairly assessed. [...]
“GMB is clear – when incidents are identified and properly assessed as not meeting expected standards, we take firm action. Our commitment to facing down discrimination and bad behaviour is unwavering.”
Nicki Eyre, managing director at workplace bullying consultancy, Conduct Change, said the report showed how harassment can become entrenched in an organisation.
Speaking to HR magazine, she said: “Entrenched behaviours can be seen as the norm, and yet the examples provided are not only unacceptable, many are indeed unlawful and possibly even criminal.
“The situation is intensified by the power dynamics at play here between the council, union and the management.”
She added that this case breaks the stereotype that only managers can inflict bullying.
“We usually think of bullying as being from the management, but we see a clear case of upward bullying and mobbing by the employees, escalating as union reps are co-opted into the situation.
“The impact on the physical and psychological health of the management as a result of the bullying, harassment and violence – the stress levels incurred due to a perceived and actual threat to life – will have been substantial.”