Criminal lawyer Adam Richards and his 13-year-old son Ned left Adelaide on December 28 and, on Thursday, were just east of Wagga Wagga, en route for their planned arrival in Canberra on February, 3.

The next day, February 4, they will attend a rally at Parliament House to present a petition urging the Federal Government to end "mandatory indefinite offshore detention of refugees" and to instead bring them to Australia for their claims to be processed.

One of the speakers at the Canberra rally will be former Labor MLA John Hargreaves.

Mr Richards said the Manus and Nauru detention centres were a national disgrace and needed to be closed. He had no illusions he would get "within cooee" of Prime Minister Malcolm Turnbull but wanted the petition presented anyway.

"We're not saying, 'Let in droves of refugees' but we are saying treat people humanely and give them a fair go," he said.

The idea for the walk to Canberra started when then 12-year-old Ned became curious about news reports last year of two refugees setting themselves alight on Nauru, one of them subsequently dying.

"Ned asked me if it would hurt to set yourself on fire and what would it feel like," Mr Richards said.

"I said, 'Ned, it would be like having cuts all over your body and your skin peeling off'.

"At which point, my 12-year-old boy put his hands over his ears and said, 'Stop'."

Ned wanted to know what could be done to prevent any similar tragedies. His dad told him nothing and was "about to offer him a whole lot of platitudes" but then realised that wasn't the answer.

"I thought, 'You're full of shit. You're his dad. You should be able to do something'. It hit me like a tonne of bricks," Mr Richards said.

"I've always taught him as a man, you protect women and children and stand up for what is right and I thought, 'There's no way I can teach my son that if I don't do it myself'."

Mr Richards' first line of action was to make what turned out to be an "inglorious" run for the Senate.

"I think I got 300 votes. I only needed 80,000 more," he said.

And next came the idea of walking to Canberra. Mr Richards said the fact the government threatened jail time for any staff who spoke out about conditions on the detention centres was proof enough for him that things were awry.

"If these camps were the holiday camps they said they were, they would never have enforced that section [of the act]. The government knows what's going on. It's a national disgrace and it needs to stop," he said.

"It's very important for me personally. I'm a very, very proud Australian. I love my country but I feel my pride in my country is under threat.

"I can either do nothing and whinge about it or I can do something about it. I want my pride back."

Young Ned, who was reading Peter FitzSimons' Kokoda in between the walking, was a more that willing participant in the journey, which is averaging about 33km a day.

"I'm immensely proud of him, I think he's amazing," Mr Richards said.

"He's never, ever pushed. He can rest when he wants and sit out when he wants. He's an exceptionally resilient young man."

Ned said on Thursday he was feeling "sore but good".

"I just wanted to do it. If it takes a 13-year-old and a 56-year-old to stand up for refugees, then we've got to do it," he said.

The cricket-mad Year Eight student had been given the option of flying back to Adelaide to play in his last cricket match of the season, but declined, preferring to stay on the walk with his dad.

"It was my grandpa who said I should keep going. I always like to finish things I've started," he said.

Ned said there had been mixed reactions on the road to their message and also from his own friends.

"Some have been good; some haven't. One didn't think I would make 15km. Well, we've done nearly 1000km now. I haven't texted him back and I don't think I will."

*Adam and Ned Richards plan to meet supporters at The Mint oval in Deakin at noon on Saturday, February 4 and then walk to Parliament House. You can follow their journey on Facebook.