Eligibility for voting

All workmen, who are above the age of eighteen years and are in service for a period of one hundred and twenty days in a period of twelve months immediately before the date of announcement of an election to be held for the purpose of section 5 in relation to such industrial establishment or class of industry, as the case may be, shall be eligible for voting, provided any interruption caused by closure, lock-out, strike, lay-off, non-availability of work or leave shall not count towards interruption of service for the purpose of this section.