Madonna has reignited her long-running feud with Lady Gaga after suggesting the A Star Is Born actress has lifted an old quote of hers and claimed it as her own.

Gaga has been busy promoting her hit movie musical for the past couple of months, and is currently pushing the critically-acclaimed film for awards season recognition.

In numerous interviews, the Born This Way hitmaker has described how she connected with her character, aspiring singer Ally, as she also struggled with similar setbacks early on in her pop career as she tried to break into the industry.

“There can be 100 people in a room and 99 of them don’t believe in you, but all it takes is one and it just changes your whole life,” she has repeatedly been quoted as saying.

However, the line has caught Madonna’s attention, because it’s eerily similar to a sentiment she first expressed decades ago.

On Monday, the Material Girl icon shared a clip from one of her old interviews from the 1980s, when she uttered a virtually identical statement.

“If there are 100 people in a room and 99 say they liked it, I only remember the one person who didn’t,” Madonna said in the Instagram Story post.

She also uploaded a photo of herself on her social media page, and wrote, “Don’t F-k with Me Monday” – a caption many followers interpreted as a thinly-veiled warning aimed at Gaga.

Her posts sparked a war between her devotees and those of Gaga, who clashed in the comments section.

Madonna has yet to clarify the meaning of her posts, but she hasn’t been afraid to criticise Gaga in the past for apparently drawing inspiration from her catalogue of hits and failing to give her enough credit.

The superstars fell out in 2012 after Madonna called Gaga’s track Born This Way “reductive” in an interview with U.S. network ABC, backing suggestions it was a rip off of her 1989 song Express Yourself.

In her 2017 Netflix documentary Gaga: Five Foot Two, the Poker Face musician revealed she was still hurt that Madonna didn’t talk to her first rather than air her objections publicly.

Expressing anger that her pop rival didn’t talk to her directly, Gaga added, “Telling me that you think I’m a piece of s**t through the media – it’s like a guy passing me a note through his friend: ‘My buddy thinks you’re hot, here’s his…’F**k you! Where’s your buddy f**king throwing up against the wall and kissing me?'”

Despite their feud, Gaga insisted she would always respect Madonna as an artist: “The thing with me and Madonna, for example, is that I admired her always and I still admire her no matter what she might think of me,” she explained. “No, I do.The only thing that really bothers me about her is that I’m Italian and from New York so, like, if I got a problem with somebody, I’m gonna tell you to your face.”