Section 37(1)(b) in West Bengal Trade Unions Rules, 1998
(b)The Returning Officer shall, with the prior approval of the Registrar, provide sufficient number of polling stations for an election in consultation with the contesting Trade Unions and shall publish, not later than 12 days before the date of the poll, a list showing such polling stations and the area for which they shall be set up. The Returning Officer shall also display the list in his office notice board and send copies thereof to the contesting Trade Unions as well as the management of the concerned establishments.