An NHS nurse is locked in a legal battle with his employer after being assaulted and abused by a patient who was known to be racist.

Colleridge Bessong, a mental health nurse, is taking legal action against Pennine Care NHS trust in Manchester over what he claims is the trust’s failure to protect him from the violent racist attack.

The patient punched Bessong eight times, threatened to stab him with a pen and said “you fucking black, I’m going to stab you now”.

The incident, in April 2017, took place at the secure residential unit where he worked helping to treat adult men under the Mental Health Act. The nurse managed to fend off his attacker but sustained injuries to his face and had to go to hospital.

Afterwards it emerged the patient was well-known to the trust for racist views. The night before the attack he had asked, “why is it all black people working in the ward?”. And hours before assaulting Bessong – who is black and African – he had expressed “hatred” of him during a meeting.

Bessong claims the trust breached its duty of care to him by not warning him of the threat he was under from a patient who was known to be racist and aggressive. His lawsuit is legally significant because it is a test case of whether employers are liable for harassment suffered by their staff.

“Our member was subjected to a sickening attack just for trying to do his job”, said Dame Donna Kinnair, the general secretary and chief executive of the Royal College of Nursing (RCN), which is supporting Bessong in his action.

“He was not only racially abused but physically attacked and threatened with a stabbing. It is an outrage that his employer knew about the threat this patient posed but neither warned our member or took measures to protect him.”

The case comes as growing numbers of NHS workers – especially A&E staff, mental health staff and ambulance crews – report being subjected to both verbal and physical harassment and assault, including racist assault. In the latest annual survey of NHS staff in England, one in seven personnel said they had been attacked by a patient, family member or member of the public.

Speaking for the first time about his ordeal, Bessong told the Guardian: “I was attacked by a patient at work and subjected to a barrage of racial abuse for no other reason than the colour of my skin. I will live with memories of that attack today.

“What made matters worse was that the patient was well-known for having a history of racist behaviour towards staff where I work, yet my employer and my manager saw no reason to take any action to deal with the risk nor did they warn me about the situation I was walking into when I commenced my nightshift”, he said.

“I know my job involves a certain amount of risk but surely my employer should have taken appropriate steps to protect me and should have at least warned me of the threat that the patient posed to me and be held accountable for failing to do so.”

The Equality Act 2010, passed by the last Labour government, obliged employers to protect their workforce from harassment. But the Conservative-Liberal Democrat coalition repealed that legislation.

The RCN began a lawsuit against Pennine Care alleging that Bessong had suffered direct and indirect race discrimination, because the trust had not protected him from a known racist patient, and also harassment. In July 2018, an employment tribunal found the nurse had suffered indirect discrimination but rejected the union’s other two claims. It appealed against that decision to the employment appeal tribunal but lost again.

It is now taking the case to the court of appeal in an action that may produce a landmark judgment on the issue of employers’ responsibility to protect their staff.

In a statement, Clare Parker, Pennine Care’s director of nursing, said: “We do not tolerate racism in any form and will always support staff if they experience abuse. We are constantly striving to improve this by listening to feedback from staff via our black, Asian and minority ethnic (BAME) network and many other channels.

“Our inpatient services provide care for people with complex mental health needs which can sometimes lead to incidents of challenging behaviour. We provide regular specialist training to help our clinical staff support patients safely and de-escalate any physical conflict.”