Australian Open organisers on alert for return of bushfire smoke

Cool temperatures and smoke-free skies gave Australian Open organisers a second day of reprieve on Friday and they will keep their fingers crossed that the haze stays away for the final weekend of preparations for the multi-billion dollar tournament.

The year's first Grand Slam begins in earnest on Monday, but organisers have already come in for severe criticism after letting qualifying continue on Tuesday and Wednesday, with noxious smoke shrouding Melbourne Park.

Fears the smoke would return on Saturday for the final round of qualifying eased on Friday, when the Environmental Protection Agency downgraded the forecast for air quality in the Melbourne area from "very poor" to "moderate".

Several of those who played on Tuesday and Wednesday suffered breathing problems, with Slovenia's Dalila Jakupovic forced to retire after a coughing fit.

Johanna Konta, whose first-round match against Tunisian Ons Jabeur will not take place until Tuesday, said she was uncertain whether she would be able to play if conditions resembled those of earlier this week.

"Today, it's nice," the British 12th seed told reporters at Melbourne Park. "But definitely when the air hasn't been good, it really hasn't been good.

"It's not ideal, and it wouldn't be ideal to play in, that's for sure. I was practising on Tuesday when it was quite bad, you can definitely feel (it). It's not a healthy environment to play in ..."

Konta's compatriot, Liam Broady, who lost his first round qualifying match on Tuesday, launched a broadside at organisers on Thursday, describing an e-mail sent to players about the smoke as a "slap in the face".

Tournament chief Craig Tiley said on Thursday he had initially been reluctant to detail numbers to players because of the complexity of the matter but on Friday organisers released full details of their Air Quality Policy.

A discussion over play being suspended would be held when fine particulate matter (PM2.5) was measured between 97 and 200 micrograms per cubic metre by the monitoring stations at Melbourne Park.

Match play would be suspended if that rating exceeded the 200 microgram mark, it said, although referees retained the discretion to "suspend, maintain or resume" matches on advice from medical experts or based on weather forecasts.

If play was suspended on the three stadium courts, the roof of the arena would be closed until the air quality reached a suitable level.

Organisers said no play or practise had been allowed at Melbourne Park on Tuesday or Wednesday, when the particulate matter exceeded 200 micrograms per cubic metre.

Australia's Prime Minister Scott Morrison on Friday described the bushfires, which have raged since September, killing 29 people and millions of animals, as "an unprecedented series of natural disasters".

As in years when soaring temperatures have baked Melbourne Park, however, there was never any real doubt that the tournament, the biggest held in the Asia-Pacific, would go ahead.

"It may look different, but the tournament will happen," Tiley said.