Lady Gaga is rumoured to be Mark Ronson's surprise guest during his Glastonbury Festival DJ set tonight.

Lady Gaga and Kevin Parker on Mark Ronson Instagram (c)

Lady Gaga and Kevin Parker on Mark Ronson Instagram (c)

The 'Poker Face' hitmaker has been spotted hanging around the VIP area behind the Pyramid stage at the world famous music event and eagle-eyed fans have put two and two together, believing she'll join the 40-year-old music maker for a secret gig in the Shangri-La area in the early hours of Sunday (26.06.16).

A source said: "She was clocked by a few people but she kept a low profile. She's been saying to Mark for ages that she wanted to come to Glastonbury. Mark is playing officially in the early hours of Sunday morning but they are trying to make another set work because she is due back in the States to meet the Dalai Lama on Sunday."

The blonde beauty flew into Worthy Farm, in Somerset, England, on Thursday and has since been spotted with Tame Impala frontman Kevin Parker, who is also set to perform today on the Pyramid stage.

The pair are friends since Ronson, Gaga and Parker took to the studio last month to star work on Gaga's forthcoming LP.

Meanwhile, Adele will thrill festival goers when she headlines the Pyramid stage tonight (25.06.16) at 22:15, but beforehand, Wolf Alice, The 1975, Alex Turner with his band The Last Shadow Puppets, Squeeze, Baaba Maal and Lewisham and Greenwich NHS Choir will warm up for the 'Hello' hitmaker.

On Friday, Muse kicked off the festival's impressive trio of headliners - which includes Coldplay - with a sensational two-hour set.