Section 30(5) in The Motor Vehicles (Driving) Regulations, 2017
(5)A retro reflective "ON TOW" sign not less than ten centimetres in height and two centimetres in width with spacing of two centimetres between the letters on white background shall be displayed on the front of the towing vehicle and at the rear of the vehicle being towed and a driver shall not tow a vehicle at night, in darkness or in adverse weather conditions unless the hazard warning lights of both vehicles are switched on:Provided that if the hazard warning lights of the vehicle being towed are not functional, it shall not be towed unless the hazard warning lights of the towing vehicle are switched on.
