Australia's highest profile unionist, Paul Howes, says his next job will not be as an MP in Federal Parliament, but he has left the door open to a future career in public life.
The 32-year-old Mr Howes is the Australian Workers Union's national secretary and has been widely tipped to enter federal politics as the ALP renews itself following the 2013 election loss.
But Mr Howes missed out on a casual Senate vacancy created by the retirement of Bob Carr last September and NSW Labor sources have told Fairfax Media the union leader was ''furious'' at being snubbed by his own Right faction, which backed former MP Deb O'Neill to take the spot.
Mr Howes confirmed he had sought the Senate vacancy but played down his failure to secure the seat on Monday in his decision to quit the labour movement.
''When it became clear to me that it would be a bruising and messy battle, I said I didn't want to be cause of that sort of conflict and division,'' he told Sky News. ''The party has had too much internal conflict in the last six years.''
Mr Howes was re-elected as the union's national secretary only last year. His bid to replace Mr Carr was met with a hostile reaction from some Labor MPs.
It also led to him falling out with his key factional ally, former NSW Labor secretary and now senator Sam Dastyari, with the pair having barely spoken for six months.
Mr Dastyari did not fight the push by current NSW Labor Party secretary Jamie Clement and Shop, Distributive and Allied Employees Association national secretary Joe de Bruyn to install former lower house MP Deb O'Neill.
Mr Howes' relationship with now Labor leader Bill Shorten also soured after Mr Shorten switched support to Mr Rudd before the 2013 federal poll.
Though Mr Howes and Mr Shorten were said to have patched up their differences, the union leader enraged many in the union movement in February when he called for a ''grand compact'' between unions and business in a speech that blindsided Mr Shorten and created a political headache for the Opposition Leader.
Mr Howes, a high profile unionist who has worked for the AWU since he was 17, said he would seek new challenges that could include study, work in the corporate sector or a philanthropic role.
He told the AWU's national executive of his intention to quit in a meeting in Perth on Monday.
''I know there has been lots of speculation today about what my motives are … but I've never had the opportunity to study, I've never had an opportunity to work outside the movement,'' he said.
Mr Howes said he was not eliminating the possibility of a career in federal politics, but insisted he was ''not stepping down from this role to pursue a career in Parliament''.
''I am not one of those who subscribe to this notion that being a trade union leader or spending your working life fighting for the rights of working people and trying to make this country a better place is somehow a bad thing if you want to go into representational politics. I think it well qualifies you.''
Mr Howes is expected to be replaced by assistant national secretary Scott McDine.
The story Paul Howes quits Australian Workers Union for a corporate life first appeared on The Sydney Morning Herald.