David Seymour says he will have his work cut out for him when he becomes Deputy Prime Minister at the end of May

As part of the coalition agreement, the Act Party leader will take over the role from Winston Peters halfway through the Government term.

He's already the Minister for Regulation and Associate Minister for Education, Finance, Health, and Justice.

Mr Seymour says his responsibilities will largely stay the same.

But he sees his promotion as a message to his supporters who were beaten down during Jacinda Ardern's Government.