The Supreme Court has dismissed Affco's challenge against a ruling the meat processor unlawfully locked out workers during collective bargaining talks.
The case relates to meatworkers in several plants being locked out at the beginning of the 2015-16 season unless they signed new individual contracts with inferior terms.
Affco had appealed to the Supreme Court because it said the workers were not employees at the time, and therefore could not be locked out.
However, the Supreme Court said even though the work was seasonal, and the workers terminated at the end of each season, Affco still had obligations to re-hire them in line with their existing union contract.
"Like the Court of Appeal, we consider that the relationship between Affco and the second respondents was sufficiently close to bring the latter within the scope of the word 'employees'."
The Meatworkers' Union said the lockouts resulted in significant hardship for the workers, and particularly those in Wairoa, who were without pay for five months.
Spokesperson Darien Fenton said workers were relieved by the ruling.
"The losses these workers have sustained, I think in places like Wairoa they've never recovered from it," she said.
"Now we can get on and work out what the compensation is for the Wairoa and various other workers around the country.
"I hope we can get to a point where we can settle this and start to build on the relationship that we've formed with Affco in the last few months with a new collective agreement, and put all this behind us."
In a statement, Affco said the ruling provided finality to the parties, addressing complex and previously undecided legal issues to the benefit of the entire industry.
It said it welcomed the findings.