Party room members desert PM Turnbull

FIRST CHALLENGES AGAINST PRIME MINISTERS:

* The proportion of party room members supporting Malcolm Turnbull is the lowest of any first-time challenge against a prime minister.

* Turnbull V Dutton 2018 48-35 (57.8 per cent of the party room)

* Hawke V Keating 1991 66-44 (60.0 per cent)

* Fraser V Peacock 1982 54-27 (66.7 per cent)

* Gillard V Rudd 2012 71-31 (69.6 per cent)