Former federal Labor leader Simon Crean, considered a giant of the labour movement, will be farewelled in Melbourne.
The 74-year-old will be laid to rest in a state funeral on Thursday at the Victorian capital's St Paul's Cathedral.
The Labor stalwart leaves behind devastated family and friends following his sudden death after exercising in Berlin last month.
The service will be live-streamed from 11am.
As ACTU vice-president, Mr Crean played a key role bringing about the Accord between unions and employers in 1983.
Elected to the Victorian seat of Hotham in 1990, Mr Crean became science minister in the Hawke government.
Narrowly missing out on the deputy leadership after Labor's election loss in 1996, he took on the position two years later after another election defeat.
After a third consecutive loss in November 2001 he was elected unopposed as leader.
Mark Latham was then narrowly elected leader over Kim Beazley, who challenged Mr Crean for the leadership in 2003.
Prime Minister Anthony Albanese will attend the service, along with former treasurer and Labor national president Wayne Swan.
Acting Opposition Leader Sussan Ley will also pay her respects on behalf of the coalition.
"As we come together to remember Simon Crean, his service is a reminder that what unites us as Australians is far greater than what divides us," she said.
"He was a man of great conviction and his contribution spans well beyond his political career.
"His lifetime of service is an example for us all."
Mr Albanese has described Mr Crean as a "thoroughly decent human being who was kind, generous and always of good humour".
After leaving politics, Mr Crean chaired the European Australian Business Council.
He is survived by his wife of 50 years Carole, daughters Sarah and Emma and grandchildren.