A fuel pipe assembly for supplying fuel to a fuel injector located within a bore of an engine cylinder head comprises a tube nut for connecting the fuel pipe to the fuel injector and a securing arrangement comprising a locking nut and a deformable clamp member for securing the fuel pipe within the tube nut. The tube nut comprises a tubular member defining an axial bore to receive the fuel pipe, a distal end shaped for cooperation with the head of the fuel pipe, and a proximal end having an attachment mechanism for engaging a compatible attachment mechanism of the locking nut. The locking nut has an axial bore to receive the fuel pipe, and an attachment mechanism for engaging a compatible attachment mechanism of the tube nut. The clamp member defines a bore to receive the fuel pipe and is deformable under compression. In a first state of engagement, the locking nut and tube nut define a volume therebetween that accommodates the clamp member in an unstrained configuration and the fuel pipe is able to move laterally. In a second state of engagement, the clamp member is compressed between the locking nut and tube nut into a strained configuration such that lateral movement of the fuel pipe is constrained.