oms and --CH2 --CHR1 --COOMe, X is a member selected from the group consisting of (1) a direct bond between the carbon and the phosphorus, ##EQU4## and Me is a member selected from the group consisting of hydrogen and a cation capable of complex formation with alkaline earth metal ions, (b) from 0 to 96.5% by weight of customary non-surface-active ingredients for washing agents and (c) from 3% to