Unknown band The ChurnUps are due to play the festival on the evening of Friday 23 June, ahead of Royal Blood and Arctic Monkeys.

Now rock group Foo Fighters have fuelled speculation they may be behind the act following a cryptic note posted on social media.

The message, scribbled by the band's lead singer Dave Grohl, used the phrase "churning up" emotions - prompting some fans to suggest it was a hint at an upcoming appearance at Worthy Farm.

"Hey, it's been a while," Grohl wrote in the letter.

"Now that we've returned from our first run of shows, I felt compelled to reach out and thank you all for being there for us.

"Every night, when I see you singing, it makes me sing harder. When I see you screaming, it makes me scream louder. When I see your tears, it brings me to tears. And when I see your joy, it brings me joy.

"But, I see you... and it feels good to see you, churning up these emotions together.

Because we've always done this together. Time and time again.

"See you soon."

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Initially, there were rumours that the Sheffield-based band Pulp was the secret act, with one Twitter user writing: "When something is churned it becomes Pulp."

Should Foo Fighters hit the stage, it will be their first time playing Glastonbury since 2017.

The group had to pull out of the event two years earlier after Grohl fractured his leg at a Swedish gig.

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The US band are famous for hits including Everlong, Best Of You and The Pretender.

Elton John, Arctic Monkeys and Guns N' Roses are headlining Glastonbury this year.