Director Jane Campion has apologised to tennis legends Venus and Serena Williams after dropping a massive clanger at the Critics Choice Awards.

Accepting her award for best director for The Power of the Dog in Los Angeles on Sunday (local time), Campion compared her professional journey to the Williams sisters in remarks lashed as unnecessary, racist and insulting.

The Wiliams had earlier received a standing ovation while introducing their film, King Richard, which was nominated in four categories.

New Zealand-born Campion saluted her “fellow, fellow, fellow” nominees for the best director’s nod, or “the guys”, as she called them. She was the only female nominee in the category, which also included Paul Thomas Anderson (Licorice Pizza), Kenneth Branagh (Belfast), Guillermo del Toro (Nightmare Alley), Steven Spielberg (West Side Story) and Denis Villeneuve (Dune”).

Campion said it was “an honour to be in the room with” the Williams sisters, before adding “Venus and Serena, you’re such marvels”.

“However, you don’t play against the guys, like I have to,” she said.

Footage from the Critics Choice telecast showed Serena clapping and laughing in the moment, while Venus’ face froze in a half-hearted smile – which has been widely screenshotted in reactions to Campion’s speech.

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“Serena and Venus didn’t have to be mentioned. Period,” author Hannah Drake tweeted.

“All [Campion] needed to do was graciously accept her award. She didn’t come up with this off the cuff. She thought of that line or approved it – talking about two black women. Leave black women alone. Just accept the damn award.”

Writer Noma Faingold was also critical.

“Is Jane Campion aware what Venus & Serena had to deal with in the whitest of sports?” she tweeted.

“What an insulting comparison. She must have not watched King Richard. Serena Williams was right when she recently wrote, ‘No matter how far we come, we get reminded that it’s not enough’.”

On Monday, Campion issued an apology for the comments.

“I made a thoughtless comment equating what I do in the film world with all that Serena Williams and Venus Williams have achieved,” she said.

“I did not intend to devalue these two legendary black women and world-class athletes.

“The fact is the Williams sisters have, actually, squared off against men on the court [and off], and they have both raised the bar and opened doors for what is possible for women in this world.”

Campion said she never intended to “minimise remarkable women”.

I love Serena and Venus. Their accomplishments are titanic and inspiring. Serena and Venus, I apologise and completely celebrate you,” she said.