The former Labor minister Mr O'Byrne announced he would be stepping down from the role on Wednesday afternoon.

Through his Facebook page, he said it was one of the toughest decisions of his life.

''Working out of Hobart and traveling across the country every week has taken its toll,'' he said.

''This job deserves complete commitment - I believe the bar should be high: justice demands it and I relish the fight.

''But I can no longer be the National Secretary our members and union require and also the husband and father my family deserve.''

Mr O'Byrne said he would be taking on a new role soon, and said that it would not be in politics.

''Being able to be at home is just the right decision for now, and I will continue to love my union and will always support the work of the labour movement,'' he said.