The paper claims Jimmy Page, John Paul Jones and Jason Bonham, the remaining members of the band, have given the singer an ultimatum to either join them or be replaced.

The story says they have been rehearsing at London’s Ritz Studio using stand-in vocalists. It quotes an unidentified source saying one of them – an American – has been so impressive the other band members are confident they could hit the road without their original frontman.

Plant, who has been working with U.S. singer Alison Krauss, hasn’t ruled out another reunion, but he has told GQ magazine that bureaucracy is what puts him off the idea.

“The endless paperwork was like nothing I’ve experienced before,” he told the U.K. style magazine. “I’ve kept every one of the e-mails that were exchanged before the concert and I’m thinking of compiling them for a book, which I feel sure would be hailed as a sort of literary version of Spinal Tap.”