Around 200 jobs are at risk in Sainsbury's stores around Northern Ireland, it has been claimed.
The trade union Unite said the jobs were under threat as a result of plans by the supermarket giant to change its management structures and cut night shift roles.
Sean Smyth of Unite the Union said: "We are deeply disappointed by proposals published by Sainsbury's which threaten to reduce its employment cohort by 2,500 across the UK, including a net reduction of 600 store trainers and 1,900 night shift positions.
"We estimate the potential impact in Northern Ireland to be more than 200 positions, affecting approximately 120 members of Unite."
The company employs around 3,900 people in 13 stores across Northern Ireland.
A spokeswoman said the company was creating 280 new roles to provide training across "a number of stores". Those management posts would replace the existing store trainers, she said. There are 870 people currently working as store trainers - one at every Sainsbury's supermarket.