Palmer United Party Senate leader Glenn Lazarus declared his party would not pass key budget measures no matter who was in charge of the government, indicating a switch in leadership may not make the upper house any easier to handle.

Prime Minister Tony Abbott on Thursday said the government would persist with the $5 GP co-payment, one of two un­popular policies remaining from the May 2014 budget. Two backbenchers and former minister Arthur Sinodinos called for it to be dumped.