Described is a turbine arrangement of a gas turbine engine, the turbine comprising: a rotor comprising a disc which incorporates a plurality of circumferentially spaced turbine blades, each blade having an aerofoil extending for a platform and a root portion securing the blade to the disc, a lock plate located at an axial end of the root portion of the blade, the lock plate comprising: a plate body having an inward facing surface which is located adjacent the blade root and an outward facing surface, radially inner and outer edge portions, and first and second circumferential edges; a head located at the radially outer edge portion of the plate body; a foot portion located at the radially inner portion of the plate body; a projection extending from the outwardly facing surface away from the turbine blade root in use, the projection being located adjacent to the foot portion, wherein the foot portion and head portion are located within slots provided at least partially by the disc and turbine blade respectively.