Left-wing lobby group GetUp has slammed Scott Morrison for an "undemocratic attack" on the organisation, after the Prime Minister announced a new crackdown aimed at curtailing its influence before the next federal election.

Mr Morrison used his speech to the Liberal Party's state conference in Adelaide on Saturday to announce a renewed assault on GetUp, blaming the group for "vile, personal attacks on our candidates" in the May poll, describing it as "misogynistic" and "shady".

Prime Minister Scott Morrison has launched a fresh attack on GetUp. Credit:AAP

He promised to "revisit GetUp's claim they are politically independent".

GetUp national director Paul Oosting hit back, defending the group's right to engage in political debate and accusing the Prime Minister of trying to set up a "kangaroo court" after the Australian Electoral Commission upheld its independence earlier this year.