The National Party will pull its support for a government bill to allow those with terminal conditions to access medicinal marijuana and instead put up its own "more comprehensive" bill on the issue.
The health select committee is due to consider its final report on the Government bill tomorrow and this is likely to be tabled in Parliament. It is still likely to be passed with support from Labour, the Greens and New Zealand First, despite National dropping its support.
National had supported it at first reading but said its ongoing support was dependent on what changes were made in select committee.
National leader Simon Bridges said the party had now decided to pull its support for that bill and develop its own measure, which he said would set out a more comprehensive and well researched regime for the use of medicinal cannabis.
"National supports greater access to high quality medicinal cannabis products to ease people's suffering but we must have the right regulatory and legislative controls in place.
"Among other things, our bill is going to make clear who can buy medicinal cannabis, who can sell it, and exactly how that will work."