Judith Collins axed from frontbench after losing National party leadership

Successor Christopher Luxon said Collins had a real passion' for new portfolio of science and innovation

New Zealand's former opposition leader Judith Collins has been demoted from the National party's frontbench and tumbled 18 places in its ranks, nearly two weeks after being ousted following her attempt to crush a rival.

New leader Christopher Luxon announced the party's caucus reshuffle on Monday. Collins, who copped the biggest demotion in the party, will take on a single portfolio - research, science and innovation - but will remain in the shadow cabinet.