The Greens, ACT and Te Pati Maori have fallen in behind National's call for a select committee inquiry into the sector.
However, Finance Minister Grant Robertson says it's not currently on the agenda.
Simplicity KiwiFund Managing Director Sam Stubbs says the country's four most profitable companies are banks.
He says the profit levels are higher than both Australia and the world.
LISTEN ABOVE
See omnystudio.com/listener for privacy information.
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com
The Breakfast Club
The World's Most Dangerous Morning Show, The Breakfast Club, With DJ Envy, Jess Hilarious, And Charlamagne Tha God!