Todd Muller is resigning as leader of the National Party.

In a statement released this morning, Todd says he has taken time over the weekend to reflect on his experience over the last several weeks as Leader of the Opposition.

"It has become clear to me that I am not the best person to be Leader of the Opposition and Leader of the New Zealand National Party at this critical time for New Zealand.

"It is more important than ever that the New Zealand National Party has a leader who is comfortable in the role."

Todd says the role has taken a heavy toll on him personally, and on his family.

"This has become untenable from a health perspective.

"For that reason I will be stepping down as Leader effective immediately.

"I intend to take some time out of the spotlight to spend with family and restore my energy before reconnecting with my community."

Todd says he looks forward to continuing to serve as a loyal member of the National Party team and Member of Parliament for Bay of Plenty.

"I will not be making any further comment.

"Please respect the privacy of my family and me."