A COMPOSITION SUITABLE FOR USE IN REMOVING SULPHUR OXIDES FROM GAS CONTAINING SULPHUR OXIDES (SUCH AS FLUE GAS) IS DESCRIBED. THE COMPOSITION ESSENTIALLY COMRISES (I) AND OXIDE OF URANIUM AND/OR A PRECURSOR THEREFOR, (II) AND OXIDE OF THORIUM AND/OR A PRECURSOR THEREFOR, AND (III) AND ALKALI METAL OR ALKALINE EARTH METAL OXIDE AND/OR A PRECURSOR THEREFOR. THE CONSITUENT (III) IS PREFERABLY SODIUM OR LITHIUM OXIDE, AND THE COMPOSITION IS PREFERABLY DISPOSED ON A CARRIER SUCH AS A-ALUMINA. THE COMPOSITION MAY BE REGENERATED AFTER USE BY EXPOSURE TO A HYDROGEN-CONTAINING GAS.