All other things being equal, the maximum difference in constituency sizes I would be comfortable with is
0% (i.e. consituencies must have the same number of voters)
0(0.0%)
2%
0(0.0%)
5%
2(5.4%)
10%
9(24.3%)
15%
4(10.8%)
20%
4(10.8%)
25%
4(10.8%)
30%
2(5.4%)
40%
0(0.0%)
50%
4(10.8%)
60%
0(0.0%)
75%
1(2.7%)
100% (i.e. one constituency could have twice as many members as another)
2(5.4%)
No limit
5(13.5%)
The reasons I would expect such variations to occur would include:
