This chapter is declared to be enacted in correlation with Titles III and IX of the Act of Congress approved August 14, 1935, designated as the Social Security Act, and with the Federal Unemployment Tax Act, and the expediency of certain provisions of this chapter depend as hereinafter set forth upon the scope and operation within this State of the provisions of said titles and of said act as originally enacted or as hereafter amended. If the Federal Unemployment Tax Act shall be interpreted or extended to impose within this State a tax with respect to employing units having in their employ less than four persons, or with respect to employing units having in their employ individuals who are not now in "employment" as defined in subdivision 1301(6)(C) of this title the Governor by proclamation within 10 days of the effective date of said extension shall so declare and thereupon and thereafter the word "employer" and the words "individual in employment," as used in this chapter shall extend to and include in the first instance all employing units having in their employ such smaller number of persons and the individuals in their employ, and in the second instance all employing units having in their employ individuals who thereafter shall be in "employment" and the individuals in their employ. Said persons shall be treated as individuals in the employ of said employer with respect to contributions and eligibility for benefits under this chapter.