Environment Minister David Speirs issued the Trust a 30-day eviction notice in June, saying Ayers House would become the new home of the state government’s SA History Trust and the 1846 building would undergo a $6.6m upgrade.

The sudden move sparked a war of words, with Speirs extending the deadline but remaining firm on the eviction as the Trust launched a petition aimed at keeping the History Trust at the North Terrace site.

The Trust said that in 1971, Premier Don Dunstan asked it to establish the Ayers House Museum and since then it had “contributed more than $25m to its operation, including millions of volunteer and staff hours to maintain and present the house to visitors from around the world”..

The Trust said it was the state’s biggest community-created and run museum and held one of Australia’s largest collections of Victorian-era artefacts, but Speirs said much of the public was unaware of its existence.

“We are very sorry to have to close the museum to the public on Sunday,” National Trust president Deborah Morgan said.

“So many people have worked so hard over 50 years to provide this service for the community and to showcase the stories and heritage of our state to people from around the world. Adelaide is losing one of its most unique attractions. Children are losing the opportunity for an unforgettable experience in a heritage place.

“Although it will be a sad day, this Sunday we will celebrate what has been achieved with a day of fun activities for children and families and a rolling program of musical performances throughout the house.”

The Ayers House Museum will be open from 10am to 4pm Sunday, admission is free.