Concerns about how workforces will be affected by boosting KiwiSaver contributions further

The National party's policy is to gradually increase the default contribution to six percent by 2032.

With employers also matching contributions, that will place New Zealand in line with Australia's current 12 percent contribution rate.

KiwiSaver provider Koura Wealth founder Rupert Carlyon says pay-rises will be cut because of higher contribution rates.

Mr Carlyon says incomes will stagger as contributions from employers and employees increase.