Harry Shearer joined by fellow band members and director Rob Reiner in claim Vivendi has not fully shared profits.

The band members from cult rock mockumentary This Is Spinal Tap have agreed to reunite in a move they claim will ensure a $400m (£321m) lawsuit against media firm Vivendi “goes to 11”.

Three of the film’s co-creators and stars have agreed to get back together to join co-star Harry Shearer in a suit against the French firm, the parent company of Universal Music.

Shearer – who also voices characters from The Simpsons such as Ned Flanders and Mr Burns – was suing Vivendi for $125m, claiming it has not properly shared profits since buying the rights to the film in 1989.

The addition of the rest of the “band members” – famed for their pretentious musical posturing and catty infighting – has boosted the size of the claim to $400m.

The off-screen reunion brings together the characters of bassist Derek Smalls (played by Shearer), lead guitarist Nigel Tufnel (Christopher Guest), lead vocalist and guitarist David St Hubbins (Michael McKean), as well as director and narrator Rob Reiner.