NOVELTY - Membrane electrode assembly comprises at least two electrochemically active electrodes separated by at least one polymer electrolyte membrane or electrolyte matrices. The electrodes have a catalyst layer in contact with the polymer electrolyte membrane or matrices. The catalyst layer comprises at least one ionomeric material, where at least the catalyst layer which is in contact with the cathode comprises a polymer comprising spiro-heterocyclic recurring units (I), as ionomeric material.    USE - The membrane electrode assembly is useful in a fuel cell, where the polymer is useful as ionomeric material in cathode.    ADVANTAGE - The membrane electrode assembly provides fuel cells with increased performance.    DETAILED DESCRIPTION - Membrane electrode assembly comprises at least two electrochemically active electrodes separated by at least one polymer electrolyte membrane or electrolyte matrices. The electrodes have a catalyst layer in contact with the polymer electrolyte membrane or matrices. The catalyst layer comprises at least one ionomeric material, where at least the catalyst layer which is in contact with the cathode comprises a polymer comprising spiro-heterocyclic recurring units of formula (I), as ionomeric material.    Either Ar1 = monocyclic, bicyclic or polycyclic tetracovalent (hetero)aromatic group; and    R1 = bicovalent group of formula ((-Ar2-Z1-Ar3-)100-n); or    Ar1 = tetracovalent group of formula (=Ar4-Z2-Ar5=); and    R1 = bicovalent group of formula ((-Ar6-Z3-Ar7-)100-n), bivalent alkyl group and/or bivalent aromatic group (both optionally substituted);    X, Z3 = N, O, or S;    Ar2, Ar3, Ar6, Ar7 = monocyclic, bicyclic or polycyclic bicovalent (hetero)aromatic group;    Z1 = bivalent alkyl group and/or bivalent aromatic group (both optionally substituted by F);    n = 0.1-99.9 mol.%;    Ar4, Ar5 = monocyclic, bicyclic or polycyclic tricovalent (hetero)aromatic group; and    Z2 = bivalent alkyl group and/or an bivalent aromatic group(both optionally substituted by F).