Ousted Liberal MP Andrew Nikolic has taken to social media to accuse left-wing lobby group GetUp! of running a "dishonest, nasty, personal campaign" that cost him his seat.

Mr Nikolic was one of the Coalition's earliest casualties on Saturday, suffering a 10.6 per cent swing against him as he lost the the marginal northern Tasmanian seat of Bass to Labor's Ross Hart.

It followed an at-times bitter campaign in which Mr Nikolic – a member of the conservative right and strong supporter of Tony Abbott – was the target of community groups that accused him of refusing to speak with those who held opposing views.