CNN  — 

New Zealand’s acting Prime Minister has attacked his country’s flag carrier airline for offering passengers a synthetic US burger critics claim could undermine national beef sales.

Winston Peters said he was “utterly opposed to fake beef” and that Air New Zealand should be promoting the country’s agricultural produce.

“Our airline should be its number one marketer,” he told journalists, according to Radio NZ. Peters is currently running the country while Prime Minister Jacinda Ardern is on maternity leave.

The airline prompted a storm of controversy when it announced the Impossible Burger, a veggie burger made from synthetic meat, would be offered to business-class passengers on its Los Angeles to Auckland route.

The meat-free Impossible Burger is made with ingredients including wheat, potatoes and coconut oil.

An MP from Peters’ New Zealand First party, Mark Patterson, said in a statement the burger was a “slap in the face” to the $6 billion New Zealand red meat sector.

He warned that the burger might pose “an existential threat to New Zealand’s second biggest export earner.”

“We have Air New Zealand actively promoting synthetic proteins which have a genetic modification component to them. This is not a good example of New Zealand Inc working together for the greater good,” Patterson added.

National Party MP Nathan Guy tweeted that it was “disappointing” to see the airline promoting genetically engineered meat when “we produce the most delicious steaks (and) lamb on the planet.”

“The national carrier should be pushing our premium products and helping sell NZ to the world,” he added.

In a statement, Air New Zealand defended its veggie burger policy, saying it “makes no apology for offering innovative product choices for its customers and will continue to do so in the future.”

The airline added that it was a significant promoter and purveyor of New Zealand produce and spends millions of dollars each year purchasing beef and lamb sourced from around the country for its in-flight meals.

The burger’s creator, Impossible Foods, describes it being made “from plants, without the destructive impact of livestock.”

“Compared to cows, the Impossible Burger uses 95% less land, 74% less water, and creates 87% less greenhouse gas emissions,” the company claimed.