§ 8. In section 234 (period after which ballot ceases to be effective) for subsection (1) there shall be substituted—
§ "(1) Subject to the following provisions, a ballot ceases to be effective for the purposes of section 233(3)(b) in relation to industrial action by members of a trade union at the end of the period, beginning with the date of the ballot—
- (a) of four weeks, or
- (b) of such longer duration not exceeding eight weeks as is agreed between the union and the members' employer."