Prime Minister Scott Morrison is getting some scathing reviews for appearing to play down the devastating bush fires surrounding Australia's largest city and the smoke choking its air, and give priority to his religious discrimination bill.

With no place in New South Wales having air quality below hazardous levels, Morrison called the news conference to announce the legislation - only to be peppered with questions about the emergency.  When asked about reports that rural fire agencies are turning to taking up commections from the public to supply food and water to their firefighters, Morrison said the federal government would be sticking with its current course of action.

"I know what the practice is and I know what the experience is and I know what's happening on the ground," Mr. Morrison said.  "That is what was intended to be set up and that is operating and I'm pleased with the way those arrangements are being worked out and if there is any other matter that would need to be addressed, it would be raised with the Commonwealth."

Sydney is under a shroud of haze caused by the fires.  New South Wales Air Quality Index guidelines state that anything over 200 is considered "hazardous" - but locations in Sydney's northwest have recorded an Air Quality Index of 2075, while Macquarie Park in Sydney's north-west recorded the state's worst air quality rating of 2,214 by 10:00 AM.

The smoke has gotten into buildings, setting off smoke alarms and causing the evacuations of trains stations and office buildings - including the Sydney Morning Herald in Pyrmont and the NSW Rural Fire Service headquarters at Olympic Park.