When calling upon employees to take strike action against their employers, trade unions must, under the relevant legislation, ensure that "so far as is reasonably practicable, every person who is entitled to vote in the ballot must:

(a) have a voting paper sent to him by post at his home address or any other address which he has requested the trade union in writing to treat as his postal address; and

(b) be given a convenient opportunity to vote by post."

Mistakes may be made that do not invalidate a strike ballot and, by extension, any strike action. However, employers and others may challenge the validity of ballots and seek injunctive relief to stop strike action on a number of grounds, including that the union had not taken reasonably practical steps to everyone entitled to vote.

In effect, this means everyone who may be called out to take part in strike action. Those not being called out on strike shouldn't get a ballot paper.

In this case, the High Court accepted that a mistake might have been made (and perhaps 100 people had been left out of the ballot), the union had attempted to ensure the accuracy of its membership lists. Furthermore, the union official is entitled to use his/her judgement in relation to these matters. They do not have to take ALL reasonable steps that someone else might take.

The injunction was refused.