The Greens have scraped into the final Senate seat in Tasmania and the Australian Electoral Commission has confirmed the return to Parliament of Labor's Lisa Singh, who has been re-elected on a wave of public support after being dropped to an otherwise "unwinnable" spot on the ALP ticket.

The AEC announced the 12 elected senators on Wednesday, with Green Nick McKim's success coming at the expense of Liberal minister Richard Colbeck - another Tasmanian who fell victim to party power plays.

Nick McKim has pipped Liberal Richard Colbeck for the final Tasmanian Senate seat. Credit:Peter Mathew

Senator Colbeck fell short when One Nation candidate Kate McCulloch overtook him and very nearly toppled Senator McKim.

The difference between the Greens' success and One Nation's failure to take the 12th seat was just 141 votes in a state of 350,000 voters.