The head of the NSW Rural Fire Service has dismissed claims by Nationals MP Barnaby Joyce that a lack of hazard reduction burns, not climate change, is the main culprit for Australia’s ongoing bushfire crisis.

The contrasting comments come as the official death toll from this bushfire season rose to 26 with confirmation that the death of a Forest Fire Management Victoria staff member in a car accident on Friday was related to the blazes.

The death of Matt Kavanagh was the third in Victoria, joining 20 fire-related deaths in NSW and three in South Australia.

Speaking on Channel Seven’s Sunrise program on Wednesday morning, Mr Joyce spoke of “green caveats” – the red tape he believes prevented firefighters from conducting hazard reduction burns ahead of the bushfire season.

“I believe, and this is my opinion, there are too many caveats that have been placed on people, let’s call them ‘green caveats’, that impede people’s capacities to fight fires,” the former deputy prime minister said.

But RFS Commissioner Shane Fitzsimmons said hazard reduction burning was challenging and the biggest impediment to completing burns was weather.

Mr Fitzsimmons said longer and hotter summers driven by climate change meant there was a “shrinking window of opportunity” for more favourable burning periods.

“Hazard reduction is absolutely an important factor when it comes to fire management and managing fire in the landscape, but it is not the panacea,” he told the ABC.

“When you’re running fires under severe, extreme or worse conditions, hazard reduction has very little effect at all on fire spread.

“It’s only when the conditions back off a bit … that you’ve actually got some prospect of slowing the fire spread.”

Mr Fitzsimmons said the RFS was now achieving up to 90 per cent of its annual burn program.

He defended fire management agencies saying claims by some politicians that “greenies” have disrupted prescribed burning were untrue.

“We are not environmental bastards; we actually work through a sensible, environmental regime,” Mr Fitzsimmons said.

“Our priorities are life, property and that environment ranks third,” he said.

Rising toll

Victorian Emergency Services Minister Lisa Neville said Mr Kavanagh and his colleague were involved in a two-vehicle crash on the Goulburn Valley Highway on Friday.

“Tragically, the 43-year-old couldn’t be revived and died at the scene,” she said.

Ms Neville said Mr Kavanagh’s colleague was taken to hospital in a stable condition.

She has warned that conditions in Victoria remained “dangerous, dynamic and volatile” with a worsening prospect for Friday.

Temperatures in fire-stricken East Gippsland are forecast to hit 40 degrees on Friday and authorities warn the forecast spells more bad news.

“The conditions we are going to see can give significant life to these fires going ahead on Friday,” she sad.

“Do not be complacent; this is not yet over,” adding there were still months of the fire season to go.

Ms Neville advised those in fire-impacted area to leave before Friday.

“Those conditions will continue right through until at least pm in the afternoon, so again, if you can, leave early on the Thursday, be out of those areas, that is the safest place to be,” she said.

In South Australia, the Country Fire Service has taken the unprecedented step of calling on police to help evacuate the Kangaroo Island town of Vivonne Bay ahead of deteriorating weather Thursday.

CFS incident controller Ray Jackson told the ABC that SA Police was helping with the evacuation.

People are being asked to move to Kingscote or Penneshaw where camp sites are being set up.

There is concern that the ongoing fire could break containment lines Thursday.

NSW, meanwhile, faces another day of very high fire danger, with residents in the Central Ranges, North Western and Southern Slopes warned to prepare their properties.

There are fears of a fire flare-up on Kangaroo Island. Photo: AAP

A wonderful place

Prime Minister Scott Morrison has used a media conference on Kangaroo Island to urge people to holiday in bushfire-affected areas.

“Australia is open, Australia is still a wonderful place to come and bring your family and enjoy your holidays,” Mr Morrison said.

“Even here on Kangaroo Island, where a third of the island has obviously been decimated – two-thirds of it is open and ready for business,” he added.

“It’s important to keep the local economies vibrant at these times.”

-with AAP