Southland farmers who slaughtered 1400 ewes in the centre of Invercargill are reuniting to remember what has become known as Bloody Friday.
The farmers were protesting against ongoing meatworkers' strikes, which had led to a three month delay in meat processing, leaving sheep on farms starving because of an extended drought.
On 9 June, 1978, they ran the starving ewes through the town before humanely slaughtering them in a side street.
Protest organiser Syd Slee says the farmers felt helpless in the face of continual action by strong unions.
He says they were desperate to have the animals killed, so decided to do something dramatic.
Mr Slee believes the protest turned the tide in meatworking industrial relations.
About 165 people are expected to attend a dinner on Saturday night where the revised edition of a book about the protest, Bloody Friday, will be launched.