Levels of harassment have increased at a Kent hospital trust that was at the centre of a bullying scandal, according to staff.
An NHS staff survey showed that 22% of workers at Medway NHS Foundation Trust said they were harassed or abused by colleagues in 2011, up 2% from 2010.
The trust said it was disappointing and bullying was "insidious".
In 2011 former Medway NHS medical director Gulzar Mufti spoke out about a culture of bullying at the trust.
Mr Mufti, who worked at the organisation for 20 years, criticised the trust after an independent report backed his bullying complaint.
Rehman Chishti, Conservative MP for Rainham and Gillingham, said he had raised the issue in Parliament at the time and fresh questions now needed to be answered.
He added: "It is completely unacceptable wherever bullying occurs, whether it's workplace or environment.
"I did raise this issue last year in Parliament with the secretary of state for health and also with the Care Quality Commission.
"It was the Care Quality Commission [who] asked Medway to provide a plan of action to prevent the actions, which at the time could be construed to be bullying.
"The question now arises, what action has followed on from the incident?"
Simon Bolton, of Unison, said: "There are people in post, and it's not necessarily their fault, who are not very good people managers.
"The NHS doesn't train or support its managers enough.
"There is a deficit in just the simple way that people treat people and treat each other at work. There's less courtesy, less respect and less good manners."
He added: "To be fair to management, when they've had it brought to their attention and they've had the evidence they've taken action.
"But really disciplinary proceedings are after the event, staff have already suffered. What we need to do is get it out of the culture."
Mark Devlin, chief executive of Medway NHS Foundation Trust, which employs about 3,900 staff, said: "Bullying is an insidious, undermining form of behaviour and certainly in this organisation we don't want to tolerate that at any level.
"Just to put this into context our rates are just over 20% and the national average in the NHS is 16%.
"That's not to say that that's acceptable but there's a considerable level of this going on in quite large organisations such as our own."