A senior official in India's Bihar state faces suspension for wearing the Hindu red mark on his forehead at work.
Lakshman Mishra, deputy director of the agriculture department, is accused of breaching a new government dress code.
He says he has worn the mark, or tilak, on his forehead at work for 30 years and it is his religious right to do so.
His colleagues support him - nearly all of them arrived at work on Friday wearing red marks in protest, and unions are threatening mass action.
Mr Mishra's troubles began in August when new guidelines were issued on what state government officials could wear at the office.
His department head, CK Anil, warned Mr Mishra that he considered his tilak to be in breach of the code.
When he refused to remove it, Mr Anil recommended him for suspension.
Mr Anil is a young, no-nonsense civil service high-flier who has already reprimanded staff in another department for spitting out betel leaf they had been chewing at work.
He is currently not taking calls from the media.
Many people in northern India wear the red holy mark on their foreheads and it is a common sight in government offices.
Mr Mishra says he has no intention of giving up the practice.
"I've been sporting the red holy dot on my forehead for the last 30 years of my career," he told the BBC.
"It has religious sentiment for me and if somebody goes on harassing me on this pretext I'll have no option but to commit suicide."
Barring some senior officials, all the employees of the state agriculture department went to work on Friday with tilaks on their foreheads in protest at his treatment.
They laid siege to Mr Anil's office and demanded he withdraw his recommendation that Mr Mishra be suspended.
"The officer's move has hurt our religious sentiments and as our protest against his order we've come to the office today adorning our foreheads with the red dot. Let him suspend all of us now," said union leader Baidyanath Yadav.
Several other state government unions are also angry and are threatening mass protests if his suspension order is not revoked with immediate effect.
Even state Agriculture Minister Narendra Singh agrees, saying "no one should be suspended for wearing a holy tilak as it's a matter of personal choice".