A fastener driving tool arranged to drive fasteners into a workpiece includes a support, a pair of sub-assemblies movably mounted on the support, each sub-assembly comprising a motor and an associated flywheel, and a nose part retractable relative to the support. The tool is arranged such that, in use, when the nose part is retracted, its movement relative to the support mechanically forces the sub-assemblies toward each other. The forcing of the sub-assemblies toward each other by the retraction of the nose part may move the sub-assemblies from an inoperative position to an operative position.