The Green Party and its European sister party, the EU Greens, are urging the New Zealand Government and the EU to make sure any trade agreement does not make medicines more expensive or punish small farmers.
Prime Minister Jacinda Ardern is in Europe this week, where she hopes to secure a breakthrough in trade negotiations with the EU after four years of talks.
She arrives in Brussels on Thursday after a string of meetings to try to knuckle down the trade deal with European leaders in Madrid - including Spanish President Pedro Sanchez, French President Emmanuel Macron, German Chancellor Olaf Scholz and Netherlands PM Mark Rutte.
In a rare joint statement ahead of the Brussels talks, the New Zealand and EU Greens have urged both sides to ensure whatever deal was struck did not make medicines more expensive by further strengthening intellectual property rights.
Strengthening those rights would likely make it more difficult and expensive to acquire cheap, generic, pharmaceuticals.
The parties also called for it to support the phase-out of fossil fuels and for a requirement that any changes in market access for agricultural products came with a condition on reducing methane emissions.
The parties warned the deal should not stimulate unsustainable agriculture for export at the expense of smaller sustainable farming both in the EU and New Zealand.
"The agreement is expected to substantially increase EU trade imports of beef/sheep meat and dairy, putting extra pressure on small EU farmers."
"The EU and NZ should redirect their strategy towards sustainable home-grown fruit and vegetables, promoting quality food and regenerative agricultural practices rather than increasing imports from the other side of the world in this regard."
Agriculture has been a sticking point in the negotiations, with the European side reportedly not budging on border protections. Primary sector leaders have raised concerns about whether the deal will offer anything significant to them and PM Jacinda Ardern has said meat and dairy are "sensitive issues" for the EU.
National Party trade spokesman Todd McClay has called for the Government not to cave in and sign unless meaningful gains for meat and dairy are not included.
"If real gains for meat and dairy aren't on the table, the Prime Minister should instruct negotiators to continue talks until a commercially meaningful offer is presented."
He said the Government had agreed to the EU's wish to protect geographical indicators - protecting the use of words such as feta and mozzarella - giving away a big bargaining chip.
"By agreeing to geographic indicators, without reciprocal gains for meat and dairy, the Government has disadvantaged New Zealand producers and made it more difficult in our future negotiations with countries like the United States, India and the Pacific Alliance."
Green Party spokeswoman on trade Golriz Ghahraman said the rules that determined how New Zealand and the EU traded with each other had to be centred on a climate-friendly basis, given the commitments of both to climate change targets.
She said for decades trade deals had prioritised "corporate elites" at the expense of the climate, workers, and the environment and that should change in this agreement.
The Greens joint statement also called on both sides to commit to making climate change "integral" to all chapters of the agreement, and to make sure a deal guarantees "the effective implementation of the Paris Agreement".
Speaking to the Herald before her trip, Ardern hinted greater access for New Zealand's agricultural products to the EU would be difficult, saying beef and dairy were "very sensitive" issues.
"It's always about what both parties can get," Ardern said.
"Horticulture and kiwifruit have a very, very uneven playing field, so that's what we're seeking," Ardern said.