A top BBC journalist has quit her job with the broadcaster over men getting paid more than women at the corporation for doing the same job.
Carrie Gracie, the BBC's China editor, blasted the Beeb for having a "secretive and illegal pay culture" in a damning open letter.
Gracie left her role as editor of the corporation's Beijing bureau last week, but will remain with the BBC.
She has made the stand after it was revealed two-thirds of BBC stars earning more than £150,000 were male.
An open letter, detailing her concerns over the "secretive" gender pay structure at the corporation, has been published on her website, and she reveals men doing the same job were paid 50% more than her, and has since turned down an "unequal pay rise".
She wrote: "With great regret, I have left my post as China editor to speak out publicly on a crisis of trust at the BBC.
"I believe you have a right to know that it is breaking equality law and resisting pressure for a fair and transparent pay structure."
She added: "It is not men earning more because they do more of the jobs which pay better. It is men earning more in the same jobs or jobs of equal value. It is pay discrimination and it is illegal."
Gracie continues that "for far too long, a secretive and illegal BBC pay culture has inflicted dishonourable choices on those who enforce it". "This must change," she adds.
She also made clear her protest was in support of the "brilliant young women" she works with.
"I don't want their generation to have to fight this battle in the future because my generation failed to win it now," she wrote.
Quitting the role she has held since 2013, Gracie said she would stay with the BBC and return to her former role in the BBC News Channel newsroom.
As #istandwithcarrie started trending after news broke, The Times reported more than 130 women working for the BBC had signed a statement of support in solidarity with Gracie.
Clare Balding, one of the the BBC's best paid female broadcasters, wrote: "This is a letter to everyone who loves and values the BBC from one of its finest journalists. @BBCCarrie has resigned as China editor. Please read and retweet. It's time for #equalpay."
In July, some of the BBC's most high-profile personalities demanded the corporation tackle its gender pay gap after it revealed the on-screen staff who earn more than £150,000 and exposed unequal pay between men and women.
Newsnight presenter Emily Maitlis, Today programme hosts Mishal Husain and Sarah Montague, journalist Victoria Derbyshire and presenter Clare Balding were among 44 women who signed an open letter to director general Tony Hall urging change.
Radio 2 presenter Chris Evans was the top earner at the BBC on more than £2m, while the highest paid woman was Strictly's Claudia Winkleman in the substantially lower £450,000 - £499,999 pay bracket.
A BBC spokesman said "fairness in pay is vital", adding: "A significant number of organisations have now published their gender pay figures showing that we are performing considerably better than many and are well below the national average.
"Alongside that, we have already conducted a independent judge led audit of pay for rank and file staff which showed 'no systemic discrimination against women'.
"A separate report for on air staff will be published in the not too distant future."