Rural independent Bob Katter says he is "very confident" both houses of Parliament will support a commission of inquiry into the banks he is designing with Nationals MP George Christensen.

Mr Katter said on Monday he would introduce a private member's bill into the House of Representatives next week to create a commission of inquiry into wrongdoing by the banks.

"We are very confident we have the numbers for a majority in the Parliament and in the upper house," Mr Katter said.

"This will be another defeat for the government on a critical issue."