A bladed rotor arrangement comprising a rotor, a plurality of rotor blades and a plurality of lock plates (48, 50); the rotor blades being mounted on the periphery of the rotor, each rotor blade comprising an aerofoil, a platform, a shank and a root; the rotor comprising a plurality of circumferentially spaced axially extending slots, the root of each rotor blade locating in a respective one of the axially extending slots in the periphery of the rotor; a plurality of lock plates being arranged at a first axial end of the rotor, the radially outer ends of the lock plates at the first axial end of the rotor engaging grooves defined by radially inwardly extending flanges on the platforms of the rotor blades, the radially inner ends of the lock plates at the first axial end of the rotor engaging a circumferentially extending groove, the circumferentially extending groove being defined by the rotor and at least one radially extending member spaced axially from the first end of the rotor, the radially outer end of the at least one radially extending member having the same radius throughout the full circumference of the at least one radially extending member; a plurality of lock plates being arranged at a second axial end of the rotor, the radially outer ends of the lock plates at the second axial end of the rotor engaging grooves defined by radially inwardly extending flanges on the platforms of the rotor blades, the radially inner ends of the lock plates at the second axial end of the rotor engaging a circumferentially extending groove, the circumferentially extending groove being defined by the rotor and at least one radially extending member spaced axially from the second axial end of the rotor, the radially outer end of the at least one radially extending member having the same radius throughout the full circumference of the at least one radially extending member, wherein the radially inner end of at least one lock plate at the first axial end of the rotor has a first foot and a second foot (64B, 64C) spaced circumferentially from the first foot, the first foot and the second foot (64B, 64C) extending radially inwardly from the radially inner end of the lock plate, and the first and second feet (64B, 64C) of the at least one lock plate are crushable and/or deformable, wherein the radially inner end of at least one lock plate at the second axial end of the rotor having a first foot and a second foot (66B, 66C) spaced circumferentially from the first foot, and the first and second feet (66B, 66C) of the at least one lock plate being crushable and/or deformable, characterised in that the bladed rotor arrangement comprises a plurality of seal plates (68, 70), at least one seal plate being arranged at the first axial end of the rotor and at least one seal plate being arranged at the second axial end of the rotor, the radially inner ends of the lock plates at the first axial end of the rotor engaging a circumferentially extending groove at least partially defined by a radially outwardly extending portion of the at least one seal plate at the first axial end of the rotor, the radially inner ends of the lock plates at the second axial end of the rotor engaging a circumferentially extending groove at least partially defined by a radially outwardly extending portion of the at least one seal plate at the second axial end of the rotor; the at least one seal plate (68, 70) having at least one anti-rotation feature (68B, 70B), each anti-rotation feature (68B, 70B) extending axially from the at least one seal plate (68, 70), each anti-rotation feature (68B, 70B) locating in a slot (45, 47) in an axial end of the root of a corresponding one of the rotor blades; and the feet (64A, 64B, 64C, 66A, 66B, 66C) of each lock plate (48, 50) resting on the anti-rotation features (68B, 70B) of the at least one seal plate (68, 70).