[en] The present invention relates to a central tube type optical fibre micro-cable with high optical fibre density including an outer sheath (4) and a polycarbonate loose tube (2) covered by the outer sheath (4). The outer sheath (4) includes a plurality of circumferentially spaced longitudinally extending grooves. During the fibre installation process, optical fibre bundles (e.g. 1) are inserted within the loose tube (2). Using the polycarbonate loose tube (2) reduces known material retraction problems, improves other mechanical properties and permits optical fibres to be blown along a longer distance in a smaller size plastic tube. The longitudinal grooves of the outer sheath (4) assists in cable peeling, reduces the friction between the cable and the tube wall during the blowing process and improves airflow. The use of a material able to reduce electrostatic absorption helps to reduce the electrostatic absorption and blowing resistance during blowing process, which increases the distance over which cables can be blown. The present invention also reduces the complexity of the production process, requires fewer tube material resources and saves overall cost.