The long-time retired Labor MP led his family's recorded eulogies on Monday as Prime Minister Anthony Albanese joined hundreds of mourners to farewell Lance Corporal Jack Fitzgibbon at an overflowing church in the NSW Hunter region.

The special forces signaller, 33, died on March 7 after a parachuting accident at RAAF Base Richmond, about 50km north of Sydney.

His superiors in the past fortnight had remarked the commando was a "gold-standard sig" and someone every platoon wanted, Mr Fitzgibbon said.

Cpl Fitzgibbon had loved the army since the age of three when his father brought home a shirt from Lone Pine Barracks near Singleton.

Wearing out that and each subsequent army shirt, the young boy was always first to spot a military vehicle or soldier passing by, declaring "he's army", Mr Fitzgibbon said.

Whether or not he was always destined to serve, there was no doubt Cpl Fitzgibbon died doing what he loved, his father said.

His love also ran deep for his parents and his two sisters, Caitlin and Grace.

"We are in no doubt about that," the retired Labor MP said, breaking down in tears.

As rain fell over St Joseph's Catholic Church in Cessnock, Di Fitzgibbon told mourners how she cherished her son's similar sense of humour.

"Although his jokes often went a bit too far, especially when his main objective was to push the sisters' buttons," she said.

Grace Fitzgibbon, a TV journalist, tearfully said she would miss the jokes, the way he always called her "sister" and his "amazing ability to stay calm in any situation".

Cpl Fitzgibbon's commanding officer in the 2nd Commando Regiment described "Fitzy" as a highly competent, modest soldier with an infectious sense of humour and a dislike of fuss.

"Looking around this church and around the Cessnock community, I envisage Jack would cringe at the attention and the ceremony surrounding today," the lieutenant colonel, who cannot be named, said.

"Fitzy was not necessarily a traditional leader, mainly because he did not want to be but he was followed by those around him all the same."

The Last Post played in the church before Cpl Fitzgibbon's casket made its way to a gun carriage to the sound of a three-gun salute.

Among the mourners were colleagues who tried to save the young corporal and a host of federal MPs who served alongside his father.

Mr Albanese and Defence Minister Richard Marles embraced their former colleague after he farewelled his son's casket, while the other side of politics was represented by Opposition Leader Peter Dutton, David Littleproud, Michael McCormack, Andrew Hastie and Barnaby Joyce.

Mr Fitzgibbon's successor as Hunter MP, Dan Repacholi, also paid his respects, alongside NSW Labor ministers Courtney Houssos, Jenny Aitchison and Yasmin Catley.

Cpl Fitzgibbon, who served a decade in the army, died a day after what the Australian Defence Force described as a routine Special Forces training activity.

He left behind partner Kass, with whom he had been preparing to get engaged and have a baby.

Australian Associated Press