People from the north of England with strong accents are perceived as being "less intelligent" and "less educated" than those in the South, a study has revealed.
Researchers at Northumbria University said "accentism" - or prejudice about accents - still exists in the UK.
The team said the issue causes "profound" social, economic and educational harm for those with "denigrated accents".
Dr Robert McKenzie, a social linguist who led the project, told The Times that “accentism” is “alive and well” in the UK, adding that most people are unaware of their “deeply embedded implicit biases”.
His team surveyed more than 300 people over four years for its Speaking of Prejudice project.
They found that students with northern accents were less likely to secure places at Russell Group universities.
He told the newspaper: “We played northern and southern speech samples to the study participants and asked them to associate positive traits, such as whether they sounded educated, with those voices.
"People were much more prejudiced when it came to accents from the north of England, for example, believing they sound less intelligent, less ambitious, less educated just from the way they speak.”
Dr McKenzie said most participants felt before taking part that they would not judge a person by their voice, but were "surprised to find out that they still held these implicit biases about certain accents".
The Social Mobility Commission has called for legislation to make socio-economic background a “protected characteristic” under the Equality Act 2010, alongside race, gender and other forms of discrimination already covered by the legislation.
Dr McKenzie cited Labour deputy leader Angela Rayner, from Stockport in Greater Manchester, as a "great example" of a victim of "accentism".
He said: “She realises that criticism of her accent is a way of taking away her message, and women in particular, are targeted this way.”
Earlier this year, when criticising the prime minister, Rayner tweeted: "I wasn't Eton educated, but growing up in Stockport I was taught integrity, honesty and decency. Doesn't matter how you say it. Boris Johnson is unfit to lead."