A curable composition comprising: (i) 2.5 to 50 wt % crosslinker comprising at least two acrylamide groups; (ii) 12 to 65 wt % curable ionic compound comprising an ethylenically unsaturated group and a cationic group; (iii) 10 to 70 wt % solvent; and (iv) 0 to 10 wt % of free radical initiator; and (v) non-curable salt; wherein the molar ratio of (i):(ii) is >0.10. The compositions are useful for preparing ion exchange membranes.