New Zealand's ambassador to the United States, Mike Moore, is facing calls for his sacking after hosting an event sponsored by a tobacco giant.

Mana Party leader Hone Harawira this morning hit out at Mr Moore, a former Prime Minister, for his decision to front the Governors and Ambassadors World Trade Reception on February 24.

Multi-billion dollar tobacco company Philip Morris was one of the event's key sponsors, along with Chevron, PhRMA and Target.

Having Mr Moore host the event undermined world-leading legislation aimed at making New Zealand smokefree by 2025, Mr Harawira said.


He called for Mr Moore to be fired from his post.

"Moore's attendance at this party is a slap in the face for all those who have worked hard to stop the tobacco companies killing thousands of New Zealanders every year, and an insult to those families who have lost loved-ones to the country's most addictive drug."

Tobacco is the biggest cause of preventable death in New Zealand, according to Smokefree New Zealand.

About 5000 New Zealanders die each year as a result of smoking, Government statistics show.

Mr Harawira said Prime Minister John Key should order foreign diplomats to cease any involvement with tobacco companies.

"All parties in the House have supported legislation aimed at reducing the impact of tobacco, and our diplomatic staff need to either get on board with that position or get another job if they can't.

"And the Prime Minister needs to fire off a strongly worded missive to Moore and the rest of our diplomats to that effect."

Australian embassy staff reportedly withdrew from the reception just hours before it started in protest at Philip Morris' involvement.


Maori Party co-leader Tariana Turia also criticised Mr Moore for hosting the event, Fairfax media reported.

She was "disturbed" at his decision to attend as a representative of New Zealand, it reported.