She was once a darling of the Howard government for winning the prized Western Sydney seat of Lindsay but Jackie Kelly has quit the Liberal Party and slammed it on the way out saying "lobbyists are running the Liberal Party".

In her resignation letter to NSW Liberal Party state director Tony Nutt, Ms Kelly said she was sick of the New South Wales branch delaying critical internal reforms to democratise the party and opening up lower house preselections to plebiscites, as recommended by former prime minister John Howard.

Former federal MP Jackie Kelly: "I would rather be outside the tent and use my voice rather than have it be silenced..." Credit:Tanya Lake

Ms Kelly wrote that she had not torn up her 19-year membership lightly but said "I would rather be outside the tent and use my voice rather than have it silenced by being inside an organisation happy to reform electoral laws but not prepared to reform itself".

She said the practice of circumventing state laws banning political donations from property developers "has been a widely used practice" and only recently exposed by ICAC.