Employers are routinely discriminating against people who stammer, rejecting them because of concerns about possible negative reactions from customers or team members, new research suggests.

A study by Dr Clare Butler, of Newcastle University Business School, published in the journal Work, Employment and Society says that people who stammer experience widespread prejudice in the jobs market.

Thirty-six men from England and Wales, ranging in age from 21 to 65 years, were interviewed and all reported routine discrimination. Some had been immediately rejected at interviews because of their stammer and others could only find jobs where they were over-qualified.

Dr Butler said two-thirds of those who were successful in gaining employment believed they were appointed because "the nature of the job meant no-one else would stick it, which often indicated a lonely or repetitive job". As a result, the men often described their workplace experiences as "mindless" or "frustrating".

"Many participants were told not only of their mismatch for the specifics of the job or the likelihood of a detrimental impact on customers, but also of the possible negative impact on team dynamics if they were appointed," said Dr Butler.

One man in his 20s who applied for an administrative post described to her how his interviewer told him "to go and look for something more suitable. He said that office work was definitely not for me because I wouldn't be able to get on with people in the office because they work hard but they also have a laugh and I wouldn't be able to join in.

"He said I could do the job mostly. He said he'd have to warn the customers about me and that most would probably understand - but he said I should look for something more suitable. When I asked 'like what?' he said outside work like gardening or something where I was on my own. I mean, can you imagine how I felt?"

Despite enduring frequent prejudice, none of those interviewed reported challenging their prospective or current employers. Dr Butler said: "This is in contrast to the movement for those with other impairments, such as dyslexia, where employees now expect, and employers are expected to make, adjustments to facilitate full access at work."

Even when they had found work they could face discrimination. A civil servant in his mid-40s reported that his manager asked him to stay away from key partnership meetings because his speech "upset the flow of the meeting".

The widespread discrimination was worsened by the changing nature of work. Dr Butler said: "More than 70 per cent of participants discussed the changing work context where they thought the roles that are, or would be, available to them are reducing. They referred to the lack of technical skills training, practical work, apprenticeships and the declining manufacturing industry. The growth of employment in service and retail has further decreased the career opportunities for people who stammer."

Reflecting on the current work climate, one man in his late 40s told her: "This voice is not what they [organisations] want."

However, this was not always the case, employers were supportive and responsive when "participants had an increased level of skill in an area where that skill was scarce or speech was not considered integral to the job requirements," said Dr Butler.

She said that many interviewees thought that their having a stammer meant they had become better listeners, and that was an important skill for the workplace. One man in his 40s told her: "Best bloody training ever for listening is having a stammer, as a kid what did we used to do but listen? I used to follow-up the meetings with emails sometimes to clarify questions that were asked in a quiet or an unspoken way and obviously missed by those trying to outsmart each other. I think every meeting should have a stammerer."

Around one per cent of the population has a stammer, 80 per cent of those are men.