Marshall told reporters a short time ago that the state’s transition committee had decided to lift the current one person per four-square-metre density cap at public venues to one person per two-square-metres from midnight Wednesday.

Gyms will be able to increase their capacity to one person per four-square-metres, while sporting competitions will be able to resume but with limits on the number of spectators.

Also from midnight Wednesday, schools will be able to resume excursions and assemblies, but students and teachers in high schools must continue to wear masks when indoors.

Home gatherings will remain capped at 10 people, while the maximum number of people allowed at weddings and funerals will stay at 50.

Singing and dancing remains banned, as does drinking or eating while standing at licensed venues.

Mask-wearing also remains mandatory in indoor public spaces, high-risk settings such as aged care facilities, personal care services and on public transport.

State emergency coordinator and Police Commissioner Grant Stevens said he “wouldn’t imagine that we are going to make wholesale changes (the new restrictions) prior to a week”.

“We would aiming for about a week, but it’s a continual reassessment and if we do see significant factors that allow us to make those changes then we will,” he said.

“It is a daily consideration.”

Marshall urged South Australian residents who are still in southeast Queensland to return home as soon as possible, after the eastern state this morning recorded 13 new locally acquired cases of COVID-19, bringing the total number of cases linked to the highly-contagious delta strain to 31.

Southeast Queensland has been in lockdown since Saturday but that will be extended until Sunday as health authorities battle to contain the outbreak.

The lockdown is in place in Brisbane, the Gold Coast, Ipswich, Lockyer Valley, Logan, Moreton Bay, Noosa, Redland, Scenic Rim, Somerset and the Sunshine Coast.

Only South Australian residents who have visited the Greater Brisbane region are allowed to travel into SA, but they must quarantine at home for 14 days once they return.

“We don’t know what this week is going to hold in Queensland (and) we know that the lockdown in southeast Queensland has been moved from three days right through to Sunday this week, so we’re saying to people at the moment South Australian residents in southeast Queensland can return to South Australia and complete 14 days of home quarantine,” Marshall said.

“This is something that everybody should consider at the moment because there is a possibility we could move to level six restrictions for South Australians as we have with those people in New South Wales.”

South Australia’s “border buffer” with Victoria has increased to 70-kilometres and authorities will from Thursday allow people in cross-border communities to travel into and out of the state to attend sporting competitions.

But Marshall said the situation in Victoria could change and people needed to be “flexible”.

Chief public health officer Professor Nicola Spurrier said South Australia’s containment of the Modbury cluster was going “very well”, but she remained on “high alert”.

“It’s only just been recently that we’ve got the Modbury outbreak under control,” she said.

“The team did an amazing job at getting so many people notified, tested and into quarantine, but there’s always a few people that haven’t used the QR codes… so there’s always the chance that there is a case in our community.”

Spurrier said SA Health was talking to the AFL and Adelaide Oval about resuming matches in Adelaide ahead of Saturday’s Showdown.

South Australia reported just one new coronavirus case today – a child who recently returned from overseas who has been in a medi-hotel since their arrival.

There are currently 28 active cases in South Australia – 21 of which are linked to the Modbury cluster. Three of those are in a stable condition in hospital.

Meanwhile, New South Wales has today recorded 207 new COVID cases, at least 50 of which were infectious in the community.

Marshall said it was now “very, very clear” that going hard and early with lockdowns has the best health and economic outcomes.

“That is now the unequivocal advice coming out of the Doherty Institute and from the Treasury Secretary Dr Steven Kennedy,” he said.

“We in South Australia have our (vaccination rollout) situation in balance and we will be getting a very significant increase in the Pfizer vaccine coming into South Australia at the end of this month and we will start to see that number increase in our state.

“I think that we are in a situation where we now have a framework which provides hope, it provides a pathway out (of lockdowns), but it is not going to occur in the next three or four weeks, so I think people have got to recognise that there are some pretty tough months ahead.

“Even after we come out of the restrictions that we’ve had after the lockdown, we still need to all be very, very vigilant.”

Both Marshall and Spurrier defended SA Health’s decision to deny Adelaide expatriate Daniel Cioffi, who is currently stuck in Brisbane quarantine, an exemption to travel to Adelaide, after his mother was diagnosed with brain cancer.

Cioffi travelled back to Australia from Spain to be by his mother’s bedside.

Marshall wrote a personal letter of support for his application to arrive in Australia.

But he said he was unable to intervene in SA Health’s decision to deny Cioffi travel from Brisbane to Adelaide.

“I don’t think we would accept in South Australia that politicians should override that expert health advice,” he said.

Spurrier said Cioffi’s mother had to “be truly end-of-life for us to take the risk for South Australia”.

“At this point in time, even if he was in South Australia, he would not be able to go to the hospital,” she said.