A method for manufacturing a water-in-water polymer dispersion which comprises subjecting an aqueous reaction mixture comprising (i) a cationic polymeric dispersant and (ii) a monomer composition comprising a) at least 5 wt.-% of a non-ionic monomer according to general formula wherein R 1 means hydrogen or C 1 -C 3 -alkyl; and R 2 and R 3 mean, independently of each other, hydrogen, C 1 -C 5 -alkyl or C 1 -C 5 -hydroxyalkyl; based on the total weight of monomers; b) at least 5 wt.-% of a cationic monomer according to general formula wherein R 4 means hydrogen or C 1 -C 3 -alkyl; Z 1 means O or NR 5 with R 5 being hydrogen or C 1 -C 3 -alkyl; Y 0 means C 2 -C 6 -alkylene, optionally substituted with one or more hydroxy groups; Y 1, Y 2, Y 3, independently of each other, mean C 1 -C 6 -alkyl; and X- means halogen, pseudo-halogen, acetate, or SO 4 CH 3 -; based on the total weight of monomers; c) 0.0001 to 1.25 wt.-% of one or more cross-linkers, based on the total weight of monomers; and d) optionally, further ethylenically unsaturated monomers; to a free radical polymerization reaction such that the resulting water-in-water polymer dispersion contains a cross-linked cationic copolymer; wherein the aqueous reaction mixture does not contain any hydrophobic monomers. (i) a cationic polymeric dispersant and (ii) a monomer composition comprising a) at least 5 wt.-% of a non-ionic monomer according to general formula wherein R 1 means hydrogen or C 1 -C 3 -alkyl; and R 2 and R 3 mean, independently of each other, hydrogen, C 1 -C 5 -alkyl or C 1 -C 5 -hydroxyalkyl; based on the total weight of monomers; b) at least 5 wt.-% of a cationic monomer according to general formula wherein R 4 means hydrogen or C 1 -C 3 -alkyl; Z 1 means O or NR 5 with R 5 being hydrogen or C 1 -C 3 -alkyl; Y 0 means C 2 -C 6 -alkylene, optionally substituted with one or more hydroxy groups; Y 1, Y 2, Y 3, independently of each other, mean C 1 -C 6 -alkyl; and X- means halogen, pseudo-halogen, acetate, or SO 4 CH 3 -; based on the total weight of monomers; c) 0.0001 to 1.25 wt.-% of one or more cross-linkers, based on the total weight of monomers; and d) optionally, further ethylenically unsaturated monomers; to a free radical polymerization reaction such that the resulting water-in-water polymer dispersion contains a cross-linked cationic copolymer; wherein the aqueous reaction mixture does not contain any hydrophobic monomers. a) at least 5 wt.-% of a non-ionic monomer according to general formula wherein R 1 means hydrogen or C 1 -C 3 -alkyl; and R 2 and R 3 mean, independently of each other, hydrogen, C 1 -C 5 -alkyl or C 1 -C 5 -hydroxyalkyl; based on the total weight of monomers; R 1 means hydrogen or C 1 -C 3 -alkyl; and R 2 and R 3 mean, independently of each other, hydrogen, C 1 -C 5 -alkyl or C 1 -C 5 -hydroxyalkyl; b) at least 5 wt.-% of a cationic monomer according to general formula wherein R 4 means hydrogen or C 1 -C 3 -alkyl; Z 1 means O or NR 5 with R 5 being hydrogen or C 1 -C 3 -alkyl; Y 0 means C 2 -C 6 -alkylene, optionally substituted with one or more hydroxy groups; Y 1, Y 2, Y 3, independently of each other, mean C 1 -C 6 -alkyl; and X- means halogen, pseudo-halogen, acetate, or SO 4 CH 3 -; based on the total weight of monomers; R 4 means hydrogen or C 1 -C 3 -alkyl; Z 1 means O or NR 5 with R 5 being hydrogen or C 1 -C 3 -alkyl; Y 0 means C 2 -C 6 -alkylene, optionally substituted with one or more hydroxy groups; Y 1, Y 2, Y 3, independently of each other, mean C 1 -C 6 -alkyl; and X- means halogen, pseudo-halogen, acetate, or SO 4 CH 3 -; c) 0.0001 to 1.25 wt.-% of one or more cross-linkers, based on the total weight of monomers; and d) optionally, further ethylenically unsaturated monomers;