The Trades Union Congress (TUC) is calling for new rights for people working over the Easter holiday.
A survey published on Good Friday shows that 6,000 people in the north-east of England who work today or Monday will not get extra money or a day off in lieu.
Kevin Rowan, Northern regional secretary of the TUC, said the issue would become more important as the region continued to move from manufacturing to the service industry.
He said workers in this UK must have the same rights as their European counterparts.
Mr Rowan said: "If you look at the past few years, and to the years ahead, the tourism and culture sectors are growing.
"They are becoming more important sectors for the regional economy.
"It's a sector where workers are not organised, not many of them are in a union, and we need to make sure that workers who work on holidays are treated by their employers."