Western Europe's de-polderisation policy was launched in the 1980's and has since spread along the coasts, especially in the U.K. where it is governed by coastal defence objectives through “managed realignment” and environmental objectives which are predominant elsewhere. Various means of de-polderisation exist: through tidal gates or breaches or sea dike removal. While physical studies on de-polderisation should be continued, it is equally important to examine the social context, favouring or not, marsh restoration since acceptance of any de-polderisation scheme largely depends on public opinion. The results of five opinion surveys carried out in France and the U.K. were thus compared and revealed diverging opinions or unexpected indiffere...