Billie Eilish has used her Glastonbury headline set to protest the US Supreme Court’s decision to end the constitutional right to abortion.

“Today is a really, really dark day for women in the US,” the 20-year-old said from the Pyramid Stage

“I’m just going to say that because I can’t bear to think about it any longer.”

She went on to dedicate Your Power, a song about older men who abuse their position, to everyone affected.

On Friday, the US Supreme Court overturned a 50-year-old ruling known as Roe v Wade that guaranteed nationwide abortion rights for women.

The decision means millions of women across the US will lose their legal right to abortion as individual states will be able to make their own laws on it.

Eilish was not the only performer at Glastonbury to protest the decision.

Earlier in the night, indie-folk star Phoebe Bridgers made a similar statement during her festival debut on the John Peel stage.

“This is my first time here. It’s surreal and amazing but I’m having a real [expletive] day,” she said.

Bridgers continued by cursing the “old” Supreme Court justices “who try to tell us what to do with our bodies”.

Eilish’s performance made her Glastonbury’s youngest-ever solo headliner, at the age of 20.

She emerged on stage shortly after 22:00, amid blasts of white noise and sub-bass before launching into her opening song, Bury A Friend.

Prowling around the stage’s catwalks and twisting her body like a character from The Exorcist, she was met by cacophonous screams and word-perfect renditions of her songs from the very first note.

“Oh boy, I love you so much,” she told the audience, which stretched right to the back of the field in front of the Pyramid Stage.

Adopting a faux English accent, she added: “How are you doin?”

The star’s set was heavily rumoured to feature a surprise appearance from Harry Styles – but, like so many Glastonbury rumours, the gossip was one step removed from reality.

Instead, the show zeroed in on Eilish, who appeared with just her brother, Finneas, and a drummer on a minimal stage with a strict red and white colour palette.

Between songs, her colourful dialogue made it seem like she was talking directly to each individual member of the crowd. She led them in breathing exercises, started a reverse Mexican wave and shared her three commandments of concert-going: “Don’t be an asshole, no judgment and have fun, bitch”.

The setlist adhered closely to her ongoing Happier Than Ever world tour, which meant it was front-loaded with fan favourites like I Didn’t Change My Number, NDA and Billie Bossa Nova, instead of big crowd-pleasers.

It was a brave move, but potentially alienating for casual observers – many of whom drifted off before the explosive closing numbers, Bad Guy and Happier Than Ever.

For diehards at the front, though, Eilish could do no wrong. Even a deep album cut like Goldwing was sung at full volume, threatening to drown her out,

“This is such an honour to be here, right now,” Eilish declared them before playing When The Party’s Over. “Thank you for letting me do this. This is such a trip and a dream.”

After tonight, the chances of her being invited back are looking pretty solid.