The Princess Margaret Rose Cave near Mount Gambier in South Australia — just across the border in Victoria — will reopen next year rather than the middle of this year, as planned.   

Expressions of interest for a tour operator for the magnificent limestone cave 3 kilometres east of the South Australian-Victorian border will go out tomorrow.

The cave closed to tourists in early 2021 after the private owners retired, amid COVID-19 restrictions that limited cross-border travel.

The cave is located in the Lower Glenelg National Park, which is run by Parks Victoria.

Parks Victoria announced almost a year ago that the tourist attraction would reopen in mid-2023 after $650,000 in work to renovate the site, including repairs to the visitor centre and safety improvements in the cave.

But, this week, a Parks Victoria spokesman said the cave would reopen next year instead.

"While the expression of interest process will be running, we'll be completing a cultural heritage management plan for further construction work," he said.

"We expect the caves will be able to reopen with the works done and an operator in place next year."

The cave was found by local property owners in the 1930s.

They requested permission from Buckingham Palace to name the site after Princess Margaret.

At the time, her sister Elizabeth was yet to be made Queen of the United Kingdom.

Local businesses hurting

The cave used to attract tourists to the nearby Victorian town of Nelson.

There is a jetty at the cave site for visitors arriving from tour boats and kayaks on the Glenelg River.

Jo Laubsch, president of the Nelson Tourist Association, bought the nearby bed and breakfast she runs with her husband after the Princess Margaret Rose Cave closed.

She said other tourism providers have told her people used to stay longer when the cave was open.

"They used to get people to stay another day, or people would come here for the caves, then find the place and might stay another day to explore the area a little bit more," she said.

She said it would be great for businesses in the town if the cave reopened.

"For example, Nelson River Cruises, they used to operate tours up to the caves, whereas now they've had to shorten their tours and obviously they're not getting as many people through because they haven't got that attraction at the end of it," she said.

Funding for works now underway at the site came from the Victorian government's $107 million Great Outdoors program.

"New infrastructure and upgraded facilities will ensure visitors and community members will be able to safely visit and enjoy the incredible wonder of Princess Margaret Rose Cave once again," then-environment minister Lily D'Ambrosio said.

"This investment will deliver a quality experience, inspiring more Victorians to get out and explore the incredible range of destinations the region has to offer."