The Single Convention's penal provisions frequently begin with clauses such as "Subject to its constitutional limitations, each Party shall . . ." Thus, if a nation's constitution prohibited instituting the criminal penalties called for by the Single Convention, those provisions would not be binding on that country. However, Professor Cindy Fazey's "A Growing Market: The Domestic Cultivation of Cannabis" points out, "Whilst this strategy may be practical politics for some countries, critics will ask why it has taken almost half a century to discover that the UN conventions conflict with a constitutional principle. The argument is particularly difficult to deploy for countries like Britain, where constitutional principles are not formalized or codified to any significant degree." However the current move in Switzerland to enshrine cannabis decriminalization in the national constitution by popular initiative could profit from this rule.