Industrial Disputes (Central) Rules, 1957
43. Electoral constituencies
Where under rule 42 the workmen’s representatives are to be elected in two groups, the workmen entitled to vote shall be divided into two electoral constituencies, the one consisting of those who are members of a registered trade union and the other of those who are not:
PROVIDED that the employer may, if he thinks fit, sub-divide the electoral constituency or constituencies, as the case may be, and direct that workmen shall vote in either by groups, sections, shops or departments.