Tane Mahuta could be protected as part of a National Park, if National returns to Government after next week's election.

The party has committed to convert Northland's Waipoua Forest into a National Park, and fund the eradication of kauri dieback disease in the park.

Conservation minister Nick Smith says it would also work with local iwi Te Roroa, to fund new tourism facilities in Northland.

The forests of Waipoua, Mataraua and Waima are the largest tracts of native forest in Northland, and are managed by the Department of Conservation.

They include the giant Tane Mahuta - the largest known Kauri tree and one of the world's largest trees.