The aged care royal commission will be the first step in “re-establishing the trust” Australians need in the sector, prime minister Scott Morrison has said.

Announcing the establishment of the commission on Tuesday, the prime minister said it would be “very future-focused”, but would also “learn from the mistakes and problems of the past”.

“I think the country is going to have to brace itself for some difficult stories,” he said. “But that’s part of the process of this royal commission, to confront these stories honestly.”

The Western Australian supreme court justice, Joseph McGrath, and former Australian public service commissioner Lynelle Briggs have been appointed as the royal commissioners.

They will release an interim report on 31 October 2019, with a final report due on 30 April 2020.

Morrison said he wanted to instil a national “culture of respect” towards elderly people.

“The royal commission will be the first step in re-establishing the trust that loved ones will be treated with dignity and with respect,” he said.

The inquiry will be based in Adelaide, where shocking abuse of residents in the state government-run Oakden nursing home was first uncovered. It will also undertake hearings around the country, and will take evidence via video.

More than 5,100 people contacted the government about the terms of reference, which were released on Tuesday.

The terms require the commissioners to look at the state of aged care provision and how to provide care for disabled residents, including young people.

It will also look at dealing with dementia, people who want to live at home, and a sustainable funding model for care and facilities.

Morrison said he expected its work would be finished within the time limit.

“[But] if more time is needed and is requested, more time is always given,” he said.

McGrath was appointed to the WA supreme court in November 2016. Before that he was WA director of public prosecutions and a senior assistant director at the commonwealth DPP.

Briggs was the chief executive of Medicare Australia and served as the public service commissioner for five years.