An employment tribunal described as "one of the country's biggest ever" is now underway in Aberdeen.
According to reports in the BBC, the tribunal, which involves over 200 offshore workers, could take up to two months to complete.
The dispute concerns staff holidays, with North Sea oil industry workers claiming they should be allowed more days off.
Catering and drilling staff are claiming that they are entitled to four weeks of paid holiday on top of the time off between their shift rotations. Their employers, however, disagree.
Oil and Gas UK, which represents the companies involved, argues that the staff already get "generous" holiday allowances.
The organisation, which aims to strengthen the long-term health of the country's oil and gas industry, is a representative body whose members are companies licensed by the government to explore and produce oil and gas in British waters.