Kaushal, a businessman and prominent Kiwi Indian community leader, was a Labour candidate for the Pakuranga electorate in the 2011 election.
He announced his resignation from the party in May and joined the National Party.
The family now has a "self-set rules" where no political discussions or debates can take place, Kaushal said.
"At home, my wife is like the Speaker of the House, she's very strong and she's made it clear about what we should and should not have in the house," Kaushal said.
Unlike in previous elections, Kaushal said he would be out convincing voters to vote for a political ideology that's totally different to that of the party his son is campaigning for.
"I don't see it as father and son opposing each other, but rather each of us doing what we both strongly believe in," he said.
"I came from a family background where we respect individual choices, and in the same way, I respect and have unconditional support for Shail and the path he has chosen."
Shail, 23, is a Puketapapa Local Board member and also Labour Party's electorate chair for Mt Roskill.
He said Kaushal's move to join National came as a surprise, but he respected the decision.
"Ultimately, he is still my dad, and the political divide has nothing to do with family...family comes first," Shail said.
"Our home has always been political and we've always had political discussions, but now with mum's new rules, we focus just on real family issues and stuff."
However, outside the home, there are no rules stopping them from making their differing political views known.
Young Shail, who entered politics with the aim of getting other young people passionate about politics, is thrilled that Jacinda Ardern is now Labour's leader.
"With her experience in Auckland Central and having held the youth portfolio for Labour in the past, Jacinda would be targeting the youth vote, and ... we can see a strong emergence of youth participation this election," he said.
"I think she would do justice to the role, and bring on board a fresh perspective, energy, and excitement New Zealand politics desperately needs."
However, Kaushal was quick to dismiss Ardern as a leader with little experience.
"Compared to Prime Minister Bill English, she has no ministerial experience, and little to no knowledge of the economy which in modern politics is an integral part of choosing a capable prime minister," he said.
"Any women or youth who care about the future and stability of this nation would be voting National this election, including my wife and younger son, I hope."