The only female Afghan barrister in England and Wales says she has become numb to discrimination after a client sacked her to appoint a white man.
Rehana Popal said other clients have told her they wanted someone white "because the judge will believe them".
She said it suggested there was a "serious concern" with how the justice system was being perceived.
The Ministry of Justice said it was committed to increasing the diversity of the judiciary.
Ms Popal, an immigration and civil law specialist barrister at 10 KBW chambers in the Temple, tweeted: "Just had a solicitor call to tell me... the client has said he doesn't want an Asian female but a white male barrister."
The barrister, who came to the UK as a child refugee, told the Victoria Derbyshire programme it had happened several times before and was "just sadly the reality" of what ethnic minorities faced at the Bar.
"They will have had to hold some prejudicial views, for them to have come to say that," she explained, "but equally there is a serious problem here in relation to perception, because clients have thought their cases will be more likely to be believed by a judge if it is presented by a white male barrister.
"That is a serious concern, because if they're having that perception, then there's something wrong with how the justice system is being perceived by outsiders and that needs to be remedied urgently."
Ms Popal said the sad thing was she had become "numb" to it as it had happened so often.
"When it happened it's almost 'eye-roll, here it happens again'. The first time it happened it was heartbreaking...but I've just got to shrug it off, move on and let my work speak for itself."
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She said she had an overwhelming response to her tweet, with both male and female lawyers saying they had been dis-instructed because of their race or religion.
"There needs to be an honest dialogue, more solicitors need to come out and say this is an issue they have faced and how they have dealt with it," she said.
The Bar Council, which represents the 15,000 practising barristers in England and Wales, told solicitors they needed to challenge clients who discriminated against barristers because of their gender, race or any other protected characteristic.
'More must be done'
Andrew Walker QC said: "Wherever discrimination does arise, it must be challenged by all branches of the legal profession. The close working relationship between barristers, their clerks and solicitors means that no-one should turn a blind eye."
The Ministry of Justice said in a statement: "The Lord Chancellor is committed to increasing the diversity of our world-renowned judiciary, and we are pleased that recent statistics show increased black and ethnic minority and gender representation.
"But we know more must be done, and we recently launched a programme to help more candidates from under-represented groups apply to be judges."
But Ms Popal said the MoJ needed to do more in the recruitment and retention of female barristers and solicitors, as they were the people who would later become judges.
"There needs to be a better campaign in recruiting them from BME backgrounds and more women, so eventually, in 10-15 years, when it comes to recruiting from the profession for the judiciary, they have a wider pool to choose from," she said.