Simon Bridges has taken to social media to explain what he thinks the "Kiwi way of life is".
Mr Bridges last week said it was under "assault" by the Tax Working Group's (TWG) recommendation the Government introduce tougher capital gains tax rules and reduce personal income tax.
"This Tax Working Group report is an assault on the Kiwi way of life," the National Party leader tweeted. "I will fight it every step of the way."
- Simon Bridges savages capital gains tax
- Judith Collins says capital gains tax will 'make Simon Bridges the Prime Minister'
Sir Michael Cullen, who headed the TWG, said a capital gains tax would introduce more "fairness" into the tax system, and that New Zealand is an "outlier" among developed nations in not having one.
"You've got some people with capital income, some people it's just all labour income or earnings from their business. Those on labour income pay the full tax. Those with capital income at the moment… [are] untaxed."
Mr Bridges' criticism of the tax as an "assault on the Kiwi way of life" came under criticism on social media, particularly Twitter - some of it from other MPs.
"You mean *your* way of life," jabbed Green MP Gareth Hughes. "Most Kiwis don't own four properties and are directors or have controlling interests in property investment companies."
"You think the Kiwi way of life is owning multiple properties and living off those capital gains? Lol, bit out of touch. Also just a tad dramatic," wrote Twitter user @bennettLmorgan.
"The Kiwi way of life is me painting over the mould in my rental property before another family moves in," responded @DomFromThe03.
Mr Bridges on Saturday uploaded a video in which he tried to explain what he thinks the "Kiwi way of life" is, and how it is under threat.
"What I meant was that all New Zealanders aspire - they want more, they want better for themselves and their families - whether that's owning a bach, whether that's starting a business, employing people and growing it, whether that's working hard and saving and investing that in KiwiSaver and other things so you can enjoy options in your later years.
"New Zealanders understand that people who work hard, who save or invest, who take risks, deserve to enjoy the fruits of their labour."
He said he understood not all Kiwis "are experiencing" the benefits of untaxed capital gain.
"Some are on the breadline, some are doing it tough and doing it day by day. I get that - I grew up in west Auckland, and my parents and I and our family didn't own our own home.
"What is also true is you don't bring people up by pulling the middle down with taxes. That sort of politics of envy, that bigotry of soft expectations, all of that ideology has never worked."
National has promised to repeal any capital gains taxes introduced by Labour. Labour has promised it won't introduce any until after the 2020 election, should it win.
National introduced the brightline tax - a capital gains tax on homes sold within two years of being purchased - in 2015. Capital gains taxes already applied to homes being bought and sold for profit, but enforcement was difficult.
Labour extended the timeframe to five years.
There are around 130,000 landlords with rental properties in New Zealand, while there are about 1.2 million owner-occupied households and more than 600,000 renting.
Home ownership is at 62.5 percent - a seven-decade low.