The town hall has commissioned an independent investigation into unions’ claims there is a culture of “bullying, harassment and racism” within its workforce, insisting it has a “zero-tolerance” approach.

As revealed by the Gazette yesterday, Unite, Unison and GMB – which between them represent thousands of workers at Hackney – sent an explosive 18-page report to all councillors and the mayor last week detailing numerous allegations of serious issues at Hackney Service Centre, the call centre behind the town hall.

They included:

• Workers’ complaints about discrimination being swept under the carpet, or resulting in them being punished for speaking out;

• A black female worker being called a member of the Taliban by a white, male colleague, who also said he would “start embracing his roots because he was white and whites used to enslave black people”;

• A manager disclosing, in front of another manager, that a black female agency worker had been a victim of domestic abuse, shouting at her: “Your partner is always pulling your hair out and you’re a walking car crash,” and: “There is always drama with you”;

• A senior white male manager making “well-known racist stereotypical comments to black staff”.

The council has now set up an independent investigation into the allegations.

Chief executive Tim Shields said: “We have appointed an external independent person to lead an investigation into the alleged issues outlined in Unite’s report.

“We met with union representatives last month who approved the choice of person and agreed the terms of reference for the investigation.”

Pivotal to the row is Unite shop steward Natasha Johnson, who was suspended for almost a year before being sacked last week.

Unite says she was disciplined and dismissed for making complaints about racist, sexist and disability discrimination from bosses and has threatened strike action if she isn’t given her job back.

Natasha, who has learning disabilities, is also in the middle of an employment tribunal over her allegations.

At a hearing last month she told the chair a manager had “a stereotype about black people” and once said to her while she rolled a cigarette: “I hope you are not smoking marijuana in work time.”

The council’s lawyer Catriona MacLaren told Natasha the comment was “at worst a poor joke” and said it was “not reasonable to have felt harassed” by the “benign” remark.

In an email to Mr Shields, Unison said: “Unison are currently dealing with a number of cases involving racism and there is a general perception amongst some of our members that racism is prevalent in the council, through both the lack of representation in the leadership team and over representation of BAME workers in the lower scales.”

Unite regional manager Onay Kasab also says the council has made it clear that if workers complain about their treatment they will be dismissed, but Hackney says this is “simply not true”.

Mr Shields added: “We are unable to comment on the circumstances of an individual case. However we strongly refute the statement made by Onay Kasab.

“Hackney Council has a zero tolerance approach to bullying, harassment and victimisation, and staff are encouraged to report all such instances.

“The council also encourages staff to make use of other policies such as the grievance and whistle blowing procedure.

“Where such matters are referred to an employment tribunal these matters are heard by an independent panel and the council has an excellent record of defending such allegations.”