1931 Census of England and Wales, General Report, Table 27 : " Constituencies returning two Members".

Constituency Population Electors
1921 1931 1921 1931
Chester County Stockport P.B. 123,309 125,490 61,862 86,284
Derby County Derby P.B. 129,796 130,811 62,497 85,542
Durham County Sunderland P.B. 173,696 171,780 74,259 103,559
Lancaster County Blackburn P.B 126,643 122,304 64,489 86,824
  Bolton P.B. 178,683 177,250 83,046 122,912
Oldham P.B. 144,983 140,314 69,695 96,518
Preston P.B. 124,001 126,388 55,521 84,243
London County City of London P.B. 13,709 10,999 44,083 43,902
Norfolk County Norwich P.B. 120,653 126,233 59,583 83,755
Southampton County Southampton P.B. 156,654 161,923 74,754 107,376
Sussex, East County Brighton P.B. 188,935 188,824 80,109 128,779