Disruption is continuing at An Post, and the company at the centre of the dispute at mail centres, says its employees' core pay is not being cut.

36 workers at I-O Systems walked off the job on Friday in a dispute over pay.

However, I-O Systems says changes in shift patterns and a reduction in working hours have affected premium pay rates.

The 36 workers who maintain automation machines in An Post sorting centres, are represented by the Communication Workers Union.

Managing Director of I-O Systems Fergal Lynam is denying union claims of pay cuts: