Paul Keating has accused Malcolm Turnbull of capitulating to conservatives in the fight for a republic, launching an extraordinary denunciation of the recently toppled leader and declaring Australians would need a "microscope" to find his true beliefs.

Mr Keating savaged the former prime minister for doing too little during almost three years in power, saying he had “failed dismally” in leading the Liberal Party back to the centre of Australian politics.

The rebuke came in response to Mr Turnbull’s secretly recorded comments in New York where he dismissed Kevin Rudd and Tony Abbott as "miserable ghosts" and signalled he would keep up his advocacy for a republic.

"Failed dismally": Former prime minister Paul Keating has attacked Malcolm Turnbull. Credit:Peter Braig, Alex Ellinghausen

Mr Keating said those remarks “make you choke on your Weeties” because Mr Turnbull had done so little on the republic in government even though he had been the head of the Australian Republic Movement in the 1990s when the issue had been voted on in a referendum.