Prime Minister Tony Abbott has been warned there are "large missiles" aimed at unpopular changes to the age pension and a group of Coalition backbenchers are pushing for the issue to be removed like other government barnacles, according to a Liberal MP.

Andrew Laming has told Fairfax Media that he is part of a group of backbenchers who have been pushing hard against the government's most unpopular policies since January.

Since surviving a "near death" spill push against him, Mr Abbott has killed and "cremated" the Medicare co-payment and backed down on holding Defence pay rises to inflation. He also dispensed with his expensive paid parental leave scheme last month as he fought for his leadership.

But Mr Abbott faces further backbench angst over the age pension, which the Coalition plans to peg to inflation rather than wages from 2017 – a move that will erode its value over coming years.