The invention relates to new 1-(2-oxyaminosulphonylphenylsulphonyl)-3-heteroaryl-ureas of the general formula (I) ##STR1## in which R.sup.1 represents an optionally substituted radical from the series comprising alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkylalkyl, aralkyl and aryl,R.sup.2 represents hydrogen or an optionally substituted radical from the series comprising alkyl, alkenyl, alkinyl and aralkyl andR.sup.3 represents an optionally substituted and/or optionally fused six-membered aromatic heterocyclic radical containing at least one nitrogen atom,the following compounds being excluded: 1-(2-methoxyaminosulphonylphenylsulphonyl)-, 1-(2-ethoxyaminosulphonylphenylsulphonyl)-, 1-(2-propoxy-aminosulphonylphenylsulphonyl)-, 1-(2-isopropoxyaminosulphonylphenylsulphonyl)- and 1-(2-butoxyaminosulphonylphenylsulphonyl)-3-(4,6-dimethyl-pyrimidin-2-yl)-urea, -3-(4,6-diethyl-pyrimidin-2-yl)-urea, -3-(4,6-dipropylpyrimidin-2-yl)-urea, -3-(4,6-diisopropyl-pyrimidin-2-yl)-urea and -3-(4,6-dibutyl-pyrimidin-2-yl)-urea, processes for their preparation and their use as herbicides.