Deputy Prime Minister Julia Gillard will no longer deliver the Sir Richard Kirby Lecture at the University of Wollongong tonight.
Ms Gillard, who is acting Prime Minister while Kevin Rudd is overseas, will remain in Canberra as debate continues over Labor's emissions trading scheme.
A university spokesperson said the lecture instead would be delivered by Ms Gillard's Parliamentary Secretary for Employment Jason Clare.
Earlier Ms Gillard pulled out of the inaugural Regional Leaders Summit, to be replaced by Maxine McKew, Parliamentary Secretary for Infrastructure, Transport, Regional Development and Local Government.
The Sir Richard Kirby Lecture will be delivered in Lecture Hall 107, the MacKinnon Building from 7-8pm at the University of Wollongong. The lecture is open to the public and admission is free.