Reports from Papua New Guinea say the 700 workers of the national power provider have voted to take strike action.
PNG is gearing up to celebrate the Independence Day holiday on Friday, but a union source says the staff at PNG Power have decided to strike only after the ceremonial events.
The Post Courier newspaper says preparations are continuing to mark 30 years of nationhood.
People throughout the country have begun wearing the colours of red, black and gold that feature on the national flag.
Many of the 19 provinces and districts have planned celebrations, that are likely to involve traditional sing-sings, string-band competitions and feasting.