Present invention relates to a stable oxidative colouring composition for keratin fibres. The aim of the inventors has been to find out an antioxidant system which is alternative to the sodium sulphite - ascorbic acid and/or its salts combination. It is furthermore the aim of the present invention that using the antioxidant system of the present invention, intensive oxidative colouration is achieved after storing said composition for a substantially long period of time. Accordingly, the object of the present invention is an oxidative dyeing composition based on at least ole oxidative dye precursor comprising further at least two structurally different reducing agents wherein the first one is selected from inorganic reducing agents and the second is an organic reducing agent and/or its salts wherein the composition is substantially free of ascorbic acid and/or its salts.