President Michael D Higgins has warned that the erosion of workers' rights poses a threat to democracy.

He made the comments at an event in Áras an Uachtaráin to commemorate organised labour movements across the globe.

President Higgins said many workers have been reduced to units of labour in workplaces that shape themselves solely around economic requirements.

He added that this has led to the working day extending beyond contracted and paid hours, and the use of technology has blurred the lines between work and home.

"What must concern us all in terms of its threat to democracy itself is what we have also witnessed across Europe in recent years - a slow but continuous decline in trade union membership, with many younger workers unaware that existing rights and such securities as there are were secured as a result of the many battles that unions have had to fight," he said.

President Higgins said early trade unionists played a major role in building and securing democracy.