In a first aspect, a method for forming a ionic polymer membrane, comprises: (i) polymerising a mixture of one or more first monomers to form an ionic polymer membrane; (ii) soaking the polymer membrane of (i) into a mixture of one or more second monomers, for a sufficient length of time to allow the solution to penetrate through the entire polymer membrane; and (iii) polymerising the monomer-coated polymer of step (ii) to form an essentially homogenous ionic polymer. In a second aspect, a method for forming a catalyst-coated ionic polymer membrane, comprises: (i) polymerising a mixture of one or more first monomers to form an ionic polymer membrane; (ii) dipping the polymer of (i) into a mixture of one or more second monomers; (iia) depositing a catalyst onto the monomer-coated polymer; (iii) polymerising the monomer-coated polymer of step (iia). The present invention also includes membranes formed using these methods.