in november 2013, grylls stepped down as party leader and wa minister for regional development. he was replaced in both roles by terry redman, while mia davies was promoted to take the third nationals' position in the barnett ministry. in august 2016, grylls returned as party leader, after redman resigned following a leadership challenge. grylls announced a raft a new policy proposals, including an increase in an existing 25-cent per tonne production rental charge set in legacy state agreements between the state and pilbara iron ore mining companies, bhp billiton and rio tinto. grylls lost his seat at the 2017 state election. his deputy, mia davies, became acting leader until she was formally elected as leader on 21 march.