Government MPs have accused National of "playing politics" for producing its own cannabis bill on the same day as the health select committee reported its findings on a Government bill.
But they have reserved judgment on National's bill, which would allow medicinal cannabis products to be treated like any other medicines and be available from pharmacies.
It would be available on the recommendation of a doctor or nurse practitioner who would authorise a photo ID card for medicinal cannabis.
Under National's bill, the products would be available as oil, tablets or under-the-tongue sprays, but not as loose-leafed cannabis.
Manufacturing would come under strict licensing conditions, with standards like other medicines, National leader Simon Bridges said.
"New Zealanders deserve greater access to high-quality medicinal cannabis products to ease their suffering but we must have the right regulatory and legislative controls in place.
"The Government's bill utterly fails both those tests, so we will vote against it," he said.
National's bill is much broader than the Government bill before Parliament, which effectively limits the use of medicinal cannabis to terminal patients because it provides a statutory defence to the use of cannabis products only to the terminally ill.
National MPs said in the select committee report that "we are uncomfortable that exercise of the terminal exemption and the statutory defence requires the illegal act of supplying cannabis to be committed".
The Government bill could still pass because it has the support of Labour, the Greens and New Zealand First, a majority.
But Bridges said he would approach other parties to see if they would support the more comprehensive National bill.
The detailed 27-page bill was drawn up by Whangārei MP and doctor Shane Reti, who has been on the health select committee considering the Government bill.
It has cleared the test to enter the next ballot for private members' bills to be drawn – which means it has been deemed sufficiently different from the two other cannabis bills that have been before the House this year to be eligible.
Health Minister David Clark said he wanted to look at the bill but said was "disappointing that they are playing politics with this".
Labour MP Louisa Wall, who chairs the Health select committee, was less charitable about the ambush, saying she had worked with National MPs on the committee in good faith.
"I do think this is a subversion of the process."
"I do think it is a kick in the guts for all the people who came and actually shared their experiences with us."
Acting Prime Minister Winston Peters said he would not comment on the bill until he had seen it.
Greens drugs spokeswoman Chloe Swarbrick said she was "stoked" that National had endorsed a comprehensive, common sense framework for medicinal cannabis and was perplexed about why the party had opposed her bill in January which allowed use of medicinal cannabis for people with debilitating illnesses, not just the terminally ill.
"We look forward to working across the House collaborative for the betterment of patients."
Bridges said the Government bill was silent on how a medicinal cannabis regime would operate in practice.
"The Government has said it will increase access now and leave it to officials to think through the controls and the consequences later. That's typical of this Government but it's not acceptable so we're putting forward a comprehensive alternative."
National's proposed regime included the following rules:
• Medicinal cannabis products to be approved in the same way medicine is approved by Medsafe.
• No loose leaf cannabis products to be approved.
• Medical practitioners to decide who should have access to a Medicinal Cannabis Card, which will certify them to buy medicinal cannabis products.
• Medicinal cannabis products would be pharmacist-only medicine.
• Cultivators and manufacturers to be licenced for commercial production with licence holders and staff to be vetted as fit and proper persons.
• licensing regime to create a safe market for medicinal cannabis products.
• Cultivators and manufacturers not allowed to be located within 5km of residential land, or 1km of sensitive sites such as schools and wahi tapu.
• No advertising of medicinal cannabis products to the public allowed.
• A review of the law by the Ministry of Health after five years.
Announcing the policy at Parliament, Bridges said National was determined to be a constructive Opposition working on new ideas and new policies.
National's bill was the result of significant work in recent months including study by MPs overseas and reflects a blend of international best practice, tailored to New Zealand.
"I encourage the Government to pick up the enormous amount of work done by National in Opposition and implement our comprehensive reforms to ensure New Zealanders in need can access high quality medicinal cannabis products to ease their suffering."
The Government has promised to hold a referendum on the personal use of cannabis at or before the 2020 election, as part of the Green Party's confidence and supply agreement with Labour.