The former Take That singer and the Led Zeppelin guitarist have fallen out over a swimming pool.
Robbie Williams is allegedly blasting music at his neighbour Jimmy Page and impersonating his bandmate Robert Plant - all because of a home extension.
According to a letter sent to the pair's local council in London, Robbie is "blasting Black Sabbath music" at Jimmy as "he knows this upsets" the 75 year old.
He's also reportedly playing songs by Pink Floyd and Deep Purple, well-known rivals of Led Zeppelin.
The letter, which is signed "Johnny", adds that Robbie has dressed up as Robert Plant by "wearing a long hair wig, and stuffing a pillow under his shirt in an attempt to mock or imitate Mr Robert Plant’s beer belly that he has acquired in his older age".
The letter writer says this is "embarrassing" because "Mr Plant was remembered for performing with his shirt open on stage, and obviously he cannot perform in his current condition".
Robbie and Jimmy have been involved in a five-year battle over a swimming pool the Take That star wants to build in his basement.
Jimmy fears excavation work will damage his mansion, located in west London's Holland Park, which was built in 1875.
In December of last year, Robbie was granted planning permission for the pool but work can't begin until councillors receive reassurance that vibration levels and ground movement issues will be monitored.
