A constitutional referendum was held in Mauritania and Senegal on 5 May 1946 as part of the wider French constitutional referendum. The proposed new constitution was approved by 92% of voters in the two territories, but was rejected by 53% of the overall vote. Voter turnout was 69%.[1]
Results
Choice
Votes
%
For
28,975
91.57
Against
2,666
8.43
Total
31,641
100.00
Valid votes
31,641
99.09
Invalid/blank votes
289
0.91
Total votes
31,930
100.00
Registered voters/turnout
46,075
69.30
Source: Sternberger et al.
References
^Dolf Sternberger, Bernhard Vogel, Dieter Nohlen & Klaus Landfried (1969) Die Wahl der Parlamente: Band II: Afrika, Zweiter Halbband, p1856 (in German)
Mauritania portal 
Senegal portal