The National Party says a parliamentary report into Pharmac's funding of cancer drugs was flawed from the beginning.
The Health Select Committee has rejected a petition that asked it to push the agency into funding two breast cancer drugs.
"Its decision-making process is robust and evidence-based," the committee's report, released on Friday, said.
"We do not believe that Parliament should attempt to influence Pharmac towards funding particular medicines."
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Nearly 34,000 people signed the petition asking for drugs Trastuzumab emtansine (sold as Kadcyla) and palbociclib (Ibrance) to be funded.
National health spokesperson Michael Woodhouse says it would have been better to "hold a broader inquiry by the select committee, and then include all of those petitions as part of the terms of reference".
Ultimately Woodhouse says the solution is more funding for Pharmac, agreeing the Government shouldn't have influence over the agency.
"We believe that Pharmac needs more money, it needs to be more transparent and it needs better timeliness."
Pharmac has doubled its spending on cancer drugs since 2011.
The Health Select Committee is made up of MPs from across the House, including members of Labour, NZ First and National.
"Many of the metavivors who submitted to us, including the petitioner, indicated that they want an inquiry into Pharmac, with a focus on its purchasing model and funding decisions," the committee's report said.
"While we were unable to agree to recommend or initiate an inquiry, we would like to see Pharmac continue to improve its action plan to promote the transparency and timeliness of its decision-making."
Cancer sufferers are shocked the Health Select Committee's rejection.
Malcolm Mulholland, whose wife Wiki has stage-four breast cancer, says the Government is keeping its head in the sand.
"Pharmac is still the envy of the world despite the fact people have their lives cut short because they simply don't fund anywhere near the amount of medicines that are funded in comparable countries."
Mulholland said when Wiki heard the news, she was visibly upset.
"That feeling is shared with fellow [breast cancer patients]. They're really shocked."
National has pledged to set up a $200 million cancer agency if elected. Labour is expected to release its plan soon.
Mulholland is mulling a career in politics, if current politicians don't help.