Over 5,000 people in the Co Tyrone town of Omagh have been urged to reject sectarianism as "intolerable" by trade union officials.
Union officials said the objective of the protest was to highlight the evil of sectarianism rather than provide a platform for politicians.
Mr Albert McFarland from the Communication Workers' Union condemned the killing of the young Catholic postman, Mr Daniel McColgan, by loyalist paramilitaries, saying no words could describe "how evil an act of sectarian violence" it had been.
Mr Kieran Gallagher from Focus, an umbrella group of voluntary and community organisations in the Omagh area, expressed his deepest sympathy to Mr McColgan's family saying people in the Co Tyrone town knew only too well "how dark a day" they had experienced.