Opposition Leader Sussan Ley has warned the government the Coalition will not be writing it a blank cheque on any tax increases that emanate from next month’s productivity roundtable or elsewhere, saying her offer of being a co-operative opponent only went so far.

Addressing her party room on the eve of the opening of the 48th parliament, Ley rejected a call by Anthony Albanese for the Coalition and Greens to respect Labor’s large majority and heed the lessons from the election at which both lost voter support, in part because of their obstructionism.