The Liberals were set to take at least 13 of the 25 House of Assembly seats - a result also predicted by an exit poll for Southern Cross TV, reinforcing polls during the campaign.

The Liberals were last in power for two years in minority backed by the Greens from 1996 to 1998, and this time party leader Will Hodgman warned against a repetition of any power-sharing arrangement.

''The thought of another Labor-Green government with a tinge of Palmer United thrown in is a frightening prospect as far as I'm concerned,'' Mr Hodgman said after he voted in central Hobart.

Tasmanians elect five members from each of five seats, and Labor was in trouble in the northern electorates of Bass and Braddon, but holding its own in southern Denison and Franklin, according to the exit poll. The fifth seat, rural Lyons, was going the Liberals' way.

The change would end four successive terms of Labor-led government, a stretch that Premier Lara Giddings said had left her with mixed emotions.

''It's difficult when you've been in power for 16 years to capture the imagination, and you must work off your record,'' Ms Giddings said.

Observers said the election was set to return the Liberals on an ''it's time'' factor, after Mr Hodgman failed to take power in 2010 when Labor went into a power-sharing government with the Greens.