She is authoritative, speaks with a posh accent, and is above all very firm: the headmistress of one of London's most prestigious girls schools is about take UBS' investment bankers to task. 

With its arched ceilings, marble floors, and wood paneling, the nearly 124-year-old St. Paul's School for Girls in the heart an affluent London neighborhood is designed to impress – academically and socially.

More than 90 percent of St. Paul's students scored in the highest academic bracket last year. The school, where annual tuition can top $27,000, has sent 48 girls to Oxford.

St. Paul's counts actress Rachel WeiszMargaret Thatcher's daughter Carole, Labour parliamentarian Harriet Harman and countless prominent women in science, the arts, law and education as «Paulinas,» as alumni are called.

Much of the school's success is down to its headmistress, 58-year-old career educator Clarissa Farr.

Fearless Girl

As formidable in tone and bearing as her school is overall, Farr has not been afraid to make enemies in the past.

Three years ago, she called out «snowplow parents» who clear away any potential obstacles for children, leaving them unable to cope with failure in the real world. 

She has also not been shy about taking parents to task over what she has termed «affluent neglect,» or parents who don't pay their children enough attention after school.

Clarissa Farr portrait 500 kopie

Now Farr is targeting the finance industry: she has been invited to speak at UBS' Broadgate offices in London on Thursday. There, she will censure the banking industry over what she calls its «patronizing» and «exploitative» treatment of women, according to prepared remarks.

«The industry has the reputation of a long hours culture and a patronizing, exploitative attitude to women who are seen as merely 'diligent' and 'safe pairs of hands' rather than as 'great minds',» Farr says.

«My Daughter Working Here?»

Farr, who is retiring this summer, founded «Dads4Daughters» through St. Paul's one year ago, to follow up on the United Nation's «HeforShe» initiative which encourages men to support gender equality. The school surveyed its younger alumni about gender diversity, and found that 73 percent of them had experienced prejudice in the workplace in some form or other.

«Fathers everywhere can ask themselves a very simple question. When he’s in the environment his own workplace, he looks around himself and says, 'would I want my daughter working here? Can I image this as a culture in which my daughter would feel comfortable and even, can I imagine my daughter leading as CEO of my organization?',» Farr said in a Youtube video to commemorate the day.

Farr's speech at UBS fits with the bank's efforts to paint itself in a softer light as marketing chief Johan Jervøe told finews.com last week, efforts to boost female in executive roles to at least one-third from 25 percent currently, as well as a push to win more business from female clients