Charles de Gaulle led the GPRF from 1944 to 1946. Meanwhile, negotiations took place over the proposed new Constitution, which was to be put to a referendum. De Gaulle advocated a presidential system of government, and criticized the reinstatement of what he pejoratively called "the parties system". He resigned in January 1946 and was replaced by Félix Gouin (SFIO). Ultimately only the PCF and the SFIO supported the draft Constitution, which envisaged a form of government based on unicameralism; but this was rejected in the referendum of May 5, 1946.