Labor Senator Lisa Singh has blamed a factional deal for her relegation to what is considered the unwinnable fourth place on the party's Tasmanian Senate ticket at the next election.

A ballot of ALP members and state conference delegates has been finalised, confirming the widely speculated outcome.

Senator Singh, who is Labor's parliamentary secretary for Environment, Climate Change and Water said she was disappointed.

"I knew it would be difficult when the factions had done a deal but that was the process, I knew that was the process, it was always going to be a hard task to beat a deal that had been done," she said.

"I am disappointed, I do thank the party members that have supported me."

Senator Singh is an unaligned member of the Left faction of the party.

She will be placed fourth on the Senate ticket behind Senators Anne Urquhart and Helen Polley and the Left faction's Manufacturing Workers Union secretary, John Short.

Tasmanian ALP State Secretary John Dowling rejected the outcome was due to Senator Singh being unaligned and said the process was robust.

"I don't agree with that, the fact is it was a postal ballot, people voted in the privacy of their own home, the votes came in and the votes were counted by the state returning officer," he said.

Senator Singh said while she was focused on her remaining two years in the Senate, she is reflecting on ALP party rules.

"It's interesting to reflect upon the different rules that play out in different states and territories ... obviously the rules in Tasmania, we don't have one vote, one value ... so I think that they are issues that can be looked at into the future, they are probably issues for the leadership of the Labor Party."

But Mr Dowling said: "At the end of the day, you have to respect the democratic processes that the party has in place."

Labor's candidates for the northern seats of Bass and Braddon have also been announced for next year's federal election.

Launceston lawyer Ross Hart will take on sitting Liberal Andrew Nikolic, while Devonport City Council Alderman Justine Keay will stand in Braddon.

Mr Dowling said they were hugely important seats for Labor.

"The seats of Bass and Braddon in many respects determine the results of federal elections, they are critical seats for the Labor Party in Tasmania."