The trade union representing retail workers has said its members, on average, saw their take-home pay fall by €109 per week over the last year.
Mandate said that for retail workers the falling wages were due mainly to reductions in working hours for staff.
The union said that the finding of a survey of members showing that on average take home pay had fallen by €109 per week had to be seen in the context of Central Statistics Office data for the first quarter of 2010 which showed that the average weekly pay for clerical, sales and service workers in the sector was just over €360 per week.
Mandate said the survey, carried out by Behaviour and Attitudes, had found that a majority of members were employed on part-time contracts, working an average of just 22 hours per week.
However it said for half of its members these working hours were spread over at least five days.
The union said working hours were also subject to frequent changes.
It said almost half of part-time workers had their working hours changed at least once per month.