A French fashion designer, known for dressing first lady Michelle Obama, has vowed to never outfit incoming first lady Melania Trump. She made the pledge in an open letter posted online on Thursday.

Sophie Theallet writes that she is boycotting Melania because she objects to the policies her husband president-elect Donald Trump espoused during the U.S. election.

鈥淎s one who celebrates and strives for diversity, individual freedom, and respect for all lifestyles, I will not participate in dressing or associating in any way with the next First Lady,鈥 Theallet writes.

The New York City-based stylist goes a step further by encouraging other fashion brands in the industry to take a stand against Trump by following her lead and refusing to dress the future first lady.

鈥淚 encourage my fellow designers to do the same,鈥 Theallet said. 鈥淚ntegrity is our only true currency.鈥

In her letter, Theallet mentions her own background as an immigrant to the U.S. as a reason why she opposes the president-elect, who used anti-immigrant rhetoric throughout his campaign.

鈥淭he Sophie Theallet brand stands against all discrimination and prejudice,鈥 Theallet says. 鈥淭he rhetoric of racism, sexism, and xenophobia unleashed by her (Melania Trump) husband鈥檚 presidential campaign are incompatible with the shared values we live by.鈥

The designer goes on to write that dressing Michelle Obama on multiple occasions over the past eight years has been a highlight and honour for her.

鈥淗er values, actions, and grace have always resonated deeply within me,鈥 she says.

Theallet appears to be the first designer to come out and publicly boycott the next first lady. It鈥檚 unclear whether Melania Trump ever planned to have stylists dress her. During the campaign trail, Melania Trump purchased all of her own clothes by designers such as Gucci, Dolce & Gabbana, Ralph Lauren and Fendi.

The online response to Theallet鈥檚 missive has been less than kind. Many of the comments under the Facebook post with her letter criticize the designer and accuse her of releasing the message as a ploy for publicity.

But other users are congratulating Theallet for standing up for her values.