Safety was at the heard of a developing debate in Australia this morning, with carriers offering sharply different responses to the ongoing ash cloud crisis.

While Australian flag-carrier Qantas has cancelled flights across the country, competitor Virgin Australia insisted it was safe to fly.

Despite assurances from AirServices Australia the Chilean volcano is not leading to any formal restrictions in local airspace, Qantas has cancelled flights from Adelaide, Tasmania and New Zealand today.

However, services to and from Melbourne have resumed.

The decision has been backed by Jetstar, which also cancel all services in and out of Adelaide, Tasmania and NZ for the rest of the day.

In turn, Tiger Airways has cancelled services between Adelaide and Melbourne and Perth and Melbourne.

“Volcanic ash from the eruption of Mt Puyehue Cordon Caulle volcano in Chile continues to cause significant flight disruptions to the Qantas network,” read a statement from Qantas.

“The Australian Volcanic Ash Advisory Centre (VAAC) has advised airspace over Tasmania, Adelaide and New Zealand has been affected.”

Still the Skies

In contrast, Virgin Atlantic has continued to operate a normal schedule, insisting it is safe to fly under or around the areas affected by ash.

Similarly, Air New Zealand is operating despite the ash cloud.

The airline yesterday operated 473 flights and carried more than 26,500 passengers around New Zealand and across the Tasman.

The VAAC said earlier the main plume of volcanic ash - which is 600 kilometres wide - is likely to remain over Adelaide for at least another day.

The plume could also get thicker over Perth in the next 24 hours, warned the VAAC.