The pair are said to have joined the mile high club in 2009 when they shared an 11-hour flight to Japan to perform at Fuji Rocks Festival.
The supposed event happened during the former Oasis frontman’s marriage to All Saints singer Nicole Appleton. They had been wed for 17 months when the encounter is said to have taken place. Appleton and Gallagher later divorced in 2014.
It was reported that Allen would be publishing details about the event in her upcoming autobiography.
When asked about the rumour, Allen told The Guardian, “I mean, I haven’t said one thing [to suggest that]. I literally have never said anything.
“Nine years ago, they first tried to print this story, and I didn’t say anything then. And now Nicole Appleton, bless her, she’s reacted to it. So that’s made it seem real. Now my Twitter feed is: ‘Oh, stupid attention seeker, she just wants another minute in the limelight.’ But I literally haven’t said anything. I haven’t even liked a tweet. Nothing.”
Last month, Appleton tweeted “One day our paths will cross Lily Allen!” You can see it below.
One day our paths will cross @lilyallen !
— Nicole Appleton (@Nicole_Appleton) April 15, 2018
Allen is said to have contacted Appleton at the time to deny that anything happened with Gallagher.
Allen’s upcoming autobiography will reportedly discuss “the trauma and grief of losing a child, the highs and lows of fame, her family story, growing up in Britpop, Glastonbury and the infamous Groucho club”.
Allen will also talk “about ‘the rebellion of her youth’, money, co-dependency, drug and alcohol dependency, eating disorders, marriage, separation, recovery, motherhood and ‘moving forward with her life’.” The book will be released later this year.
Her new album, ‘No Shame’ is set for release on June 9.