New Zealand Aluminium Smelters has been denied the right to take a long-running employment case to the Supreme Court.
At issue was the right of employees to get an extra day's leave for each day's public holiday.
The company said this should not apply if the public holiday fell on a day when the employee would not be working anyway.
But the workers said the law was clear they should get an extra day anyway.
The Court of Appeal agreed with them, and the smelter then sought leave to take the case to the Supreme Court.
That court has now declined to hear the case.
