Harrison Fischer can reel off the details of virtually every electorate and sitting member in Federal Parliament.

It's not because he's the son of former deputy prime minister and National Party leader, Tim Fischer.

It's because he has autism and has a prodigious memory for certain things.

Politics is one of his intense interests — along with sporting statistics, aeroplanes and Pokemon.

"I live in the seat of Indi, held by Cathy McGowan who's an independent on about a 4.5 per cent margin," he says.

"The Liberals ran second at the last election, the first time it's been marginal since 1931 when Labor lost the seat."

But unlike his famous father, Harrison is a Labor man. His political idol is Julia Gillard.

And he believes Labor will win the next election in a landslide.

There's a hint of frustration on Tim Fischer's face, but he says he is just delighted that his son takes an interest in politics.

"And maybe one day, he'll switch back," he says.

"Who knows?"

Harrison has a flair for political and AFL statistics. ( Australian Story: Ben Cheshire )

Defying expectations

Harrison was five years old in 1999 when his father announced he was stepping down as deputy prime minister, citing a "convergence of certain political and personal factors".

The resignation prompted a rare display of public equanimity in Parliament, with then-Labor leader Kim Beazley describing Tim Fischer as "one of the genuinely loved people in this place — you are going to be missed very much by us".

One of the key personal factors behind the resignation was Harrison's diagnosis with autism.

"It was shattering, it was disappointing, it was challenging. And initially I pushed back against it in a somewhat crazy way," Tim says.

Harrison as a toddler with his Dad, Tim. ( Supplied: Fischer family )

Tim's wife, Judy Brewer, vividly remembers the doctor's negative tone.

"We were told, 'your son has autism. He'll probably never live independently, he will probably never have a job, he will probably never be able to do the other things that other children or adults do'.'"

It was only after Harrison's diagnosis that Tim realised that he himself had a degree of autism.

Though it was never formally diagnosed, he recognised that some of his characteristics, such as his lifelong fascination with railways and transport, were tell tale signs of a mild form of autism.

The Fischer family: Judy, Tim, Dom and Harrison. ( Supplied: Fischer family )

'I'm proud to be autistic'

Sorry, this video has expired Finding work can be difficult for school leavers facing challenges such as autism, but Harrison has found a job that suits him perfectly.

Growing up with autism wasn't easy for Harrison. Through his school years he was frequently bullied.

But now aged 25 with a job and living independently, he wants to be a role model for young people with autism.

He calls himself "proudly autistic".

"I'm proud to have autism, I'm proud to be who I am, and I don't have any regrets about that," Harrison says.

"I don't think I would be who I am without it. Everyone has stuff that makes you unique, and for me autism is one of the big things that makes me unique."

He works part-time as a technology assistant at St Monica's Primary School in Wodonga, Victoria, and is a mentor to students on the autism spectrum.

He's also a popular figure in the nearby housing development of Elmwood, where he runs an AFL tipping competition, utilising his vast knowledge of football statistics.

For his parents, seeing Harrison gainfully employed and making friends is more than they had ever hoped for when he was small.

"When I look at where he is now, I am absolutely astounded how far he has come," Judy says.

"He does have a disability and he does need help in doing everyday tasks.

"But from needing help 24 hours a day, he now needs only a tiny bit of help to get himself organised and off to work."

Harrison, 25, is a proud mentor for all students, but especially those with autism. ( Australian Story: Ben Cheshire )

The next move: Harrison was eager to work after finishing high school, he just needed an employer to give him a chance. ( Australian Story: Ben Cheshire )

'You hope and pray': Tim Fischer's cancer battle

Harrison's growing independence has been a source of comfort to his parents with the recent news that Tim is battling leukaemia.

Like any parents who have a child with a disability, they were worried for a long time about what would happen to their child when they were gone. Who would look after Harrison?

"Obviously when you're facing an illness as serious as what Tim is going through at the moment, it does focus your mind on what happens in the future," Judy says.

Speaking for the first time about the illness in an interview with the ABC's Australian Story, Tim acknowledged that his prognosis was "not good".

"It's as it is. At three score plus 12, you take the cards that you're dealt with, and hope and pray," he told the program.

The former Australian Army conscript attributes his condition to exposure to the chemical Agent Orange during his service in Vietnam in the 1960s.

Tim Fischer served in the Vietnam War. ( Supplied )

Tim has faced a series of cancers in the last few years, starting with bladder cancer, then prostate cancer, two melanomas, and now acute myeloid leukaemia.

"I had operations in First Battalion Royal Australian Regiment. Agent Orange was widely used in part, but not all of the operational area," he says.

"At least one specialist has suggested my immunity broke down a lot more quickly as a direct consequence."

Asked whether it seems a cruel price to pay for serving his country, he pauses, and then says with a sigh, "Yes. That's true."

"But many had their lives shortened by service in Vietnam."

Harrison finds the topic too confronting to linger on.

"I struggle to think about what he says with that, because it's a bit sad that Dad's not well and he could die any day, probably," he says.

"It makes me feel really upset."

Sorry, this video has expired Tim Fischer is determined to keep up his busy schedule while undergoing treatment for leukaemia.

The former deputy prime minister, National Party leader, trade minister, Member for Farrer and 16 times acting prime minister has embarked on a new round of chemotherapy in Melbourne.

Reluctant to slow down his famously hectic schedule, he has been given a leave pass from hospital for a few hours to launch his latest book on trains, Steam Australia, in conjunction with the National Library.

He feels a sense of relief that Harrison — and younger son Dominic — have found their place in the world.

"I'm just so happy that Harrison has reached a degree of tranquillity and positive approach to his life," he says.

"I will eventually leave this planet Earth, sooner or later, in the knowledge that Harrison is now far better placed than he was 10 years ago or 20 years ago."

Harrison Fischer says he is "proudly autistic". ( Australian Story: Ben Cheshire )

Watch Australian Story's Call Me Harrison ABC iview or Youtube.