Abstract: An injection mould for injection moulding an article having a base and a sidewall, the injection mould comprising: first and second mould parts which are adapted to be connected together in a closed configuration so as to define a mould cavity there between, the mould cavity having a base portion and a sidewall portion, an injector for injecting into the mould cavity molten material to be moulded into the article, at least one portion of one of the first and second mould parts being movable when the first and second mould parts are in the closed configuration so as to vary the volume of the mould cavity, an actuator for selectively moving the at least one portion of one of the first and second mould parts in first and second directions so as to increase and reduce, respectively, the volume of the mould cavity.