Alexandra Wilson, 25, who works as a criminal and family barrister, said she was ‘almost in tears’ after they repeatedly failed to recognise her profession on Wednesday.

In a viral Twitter thread, she wrote she was ‘completely exhausted’ of ‘having to constantly justify my existence at work’. Kevin Sadler, the acting chief executive of Her Majesty’s Courts and Tribunals Service, has apologised and promised to launch an investigation.

It comes after a Ministry of Justice report found only 9% of senior barristers are from Black, Asian, and minority ethnic (BAME) backgrounds.

Ms Wilson, from Essex, said a security guard asked to take her name so he could find it on the list of defendants when she arrived at court.

She said: ‘I explained I was a barrister. He apologised and guided me through security. At this point I tried to shrug it off as an innocent mistake.’

After meeting with her client, she attempted to enter the courtroom to discuss the case with the prosecutor – but was stopped by a member of the public who believed she was a journalist.

An usher who recognised her job title told her to go inside, but as she opened the door another solicitor or barrister advised her to wait outside for the court to call her in.

Writing on Twitter, Ms Wilson continued: ‘I explained I’m a barrister. She looked embarrassed and said “oh. I see”. ‘She turned back around and I walked towards the prosecutor, ready to have our conversation. ‘Before I got there the clerk, VERY loudly, told me to leave the courtroom and said the usher would be out shortly.

Before I could respond she then asked if I was represented. ‘I, AGAIN, explained that I am a defence barrister trying to speak to the prosecutor.

She looked at me, said “oh right, ok” and continued with what she was doing.’ Ms Wilson, who is the author of In Black And White: A Young Barrister’s Story of Race and Class in a Broken Justice System, has since lodged a formal complaint. She said: ‘This really isn’t ok though. I don’t expect to have to constantly justify my existence at work.’

Responding to her tweets, HMCTS acting chief executive, Kevin Sadler, said: ‘I’m very sorry about your experience at court yesterday – it is totally unacceptable behaviour.’

He said he would be investigating the role of his staff and contractors ‘as a matter of urgency’ adding: ‘This is not the behaviour anyone should expect and certainly does not reflect our values.’ Ms Wilson said she is ‘grateful’ for the apology and hopes it ‘leads to some real change’.

It comes as figures reveal people from BAME backgrounds are less likely to be successful when applying to become a judge. Only 9% of senior barristers are from ethnic minority backgrounds.

A Ministry of Justice report found last week that BAME people are ‘over-represented in applications for judicial appointment’ but are ‘less likely to be successful’.