ROBERT PLANT said Led Zeppelin are incomplete without original drummer John Bonham.
Plant said the band therefore cannot reunite for a full tour and album without Bonham, who died in 1980.
Speaking to Absolute Radio, he said: "The reason that it stopped was because we were incomplete, and we've been incomplete now for 29 years."
There have been rumours that Led Zeppelin were planning a full reunion having played a one-off gig at London's O2 Arena in 2007.
But Plant said he was not interesed in bringing the band back properly as he didn't want to jeopardise Led Zeppelin's legacy.
He explained: "I think the thing about it is really, is that to visit old ground, it's a very incredibly delicate thing to do.
"The disappointment that could be there once you commit to that and the comparisons to something that was basically fired by youth and a different kind of exuberance to now, its very hard to go back and meet that head on and do it justice."
Plant did confirm that he had started work on new material with Alison Krauss, with whom he collaborated on the acclaimed 2007 album 'Raising Sand'.
He joked: "Last night's title for the next project was called 'A Gated Community', because it's like being in a loony bin."