Former US National Security Agency contractor Edward Snowden today accused the New Zealand government of spying on its citizens, just days before the country goes to the polls in national elections.

If you live in New Zealand, you are being watched, he wrote in an opinion piece for the Intercept, an online news site run by journalist Glenn Greenwald. In it, he said that he regularly saw data from New Zealand when he was working for the NSA.

His allegation threatens to upend what has so far been a predictable campaign a poll three days agoshowed Prime Minister John Key as the choice of 61.6 percent of voters, compared to 17.9 percent for his closest challenger, according to the New Zealand Herald.

Snowden's charges drew a quick rebuttal from Mr. Key, who vigorously denied that New Zealands Government Communications Security Bureau (GCSB) runs a mass surveillance program.

There is not, and never has been, mass surveillance of New Zealanders undertaken by the GCSB, he said in a statement.

In his op-ed, Snowden urged New Zealanders to vote, writing that come Sept. 20, New Zealanders have a checkbox of their own.

If you live in New Zealand, whatever party you choose to vote for, bear in mind the opportunity to send a message that this government wont need to spy on us to hear: The liberties of free people cannot be changed behind closed doors. Its time to stand up. Its time to restore our democracies. Its time to take back our rights. And it starts with you.

Snowden says Key's government, through the GCSB, funnels mass surveillance data into the NSA's XKeyscore program. He writes:

The GCSB provides mass surveillance data into XKEYSCORE. They also provide access to the communications of millions of New Zealanders to the NSA at facilities such as the GCSB station at Waihopai, and the Prime Minister is personally aware of this fact. Importantly, they do not merelyuseXKEYSCORE, but also actively and directly develop mass surveillance algorithms for it. GCSBs involvement with XKEYSCORE is not a theory, and it is not a future plan. The claim that it never went ahead, and that New Zealand merely looked at but never participated in the Five Eyes system of mass surveillance is false, and the GCSBs past and continuing involvement with XKEYSCORE is irrefutable.

Key went on New Zealand television programs over the weekend to say that New Zealand intelligence agencies considered setting up a mass surveillance system, but ultimately decided against it.

More here:

New Zealand spying row: Snowden as election wildcard?