Process for the production of water-soluble auxiliaries for the papermaking industry by reacting(a) 1 part by weight of a polyamidoamine obtained by condensing 1 mole of a dicarboxylic acid having from 4 to 10 carbon atoms with from 0.8 to 1.4 moles of a polyalkylene polyamine having from 3 to 10 alkyleneamine units and containing up to 8 ethyleneimine units per basic nitrogen atom with (b) 0.1 to 4 parts by weight of an .alpha.,.omega.-dichloro polyalkylene oxide obtained by reacting a polyalkylene oxide having from 8 to 100 alkylene oxide units with a compound selected from the group consisting of a thionyl chloride and phosgene and then cleaving the reaction products by heating them to a temperature of from 70.degree. to 150.degree. C. in the presence of a tertiary amine as catalyst,as crosslinking agent, at a temperature above 20.degree. C. in aqueous solution or in a water-soluble organic solvent, the reaction being carried out to a point at which the viscosity of an aqueous solution containing 20% by weight of auxiliary is from 300 to 2,500 mPas.