The political exchanges over the Northland by-election have spread to Korea.
A spat between government ministers and New Zealand First leader and by-election candidate Winston Peters blew up as the Prime Minister prepared to leave Korea after signing the two countries' Free Trade Agreement (FTA).
John Key said the FTA was good for the people of Northland and Mr Peters would drive a dagger through its heart when it came to the parliamentary vote.
Mr Peters said that was utter drivel and showed how desperate National was feeling about Northland.
He has also criticised the deal struck by National with Korea, saying he was offered a much better deal by former president Roh Moo-Hyun when he was New Zealand's foreign minister in the late 2000s.
Mr Peters told Checkpoint his party would not vote against the FTA but would continue to point out that New Zealand could have got a far better deal.
Trade Minister Tim Groser said he was the chief negotiator at the time and Mr Peters' claims were not true and he was offered very little.
By-election too close to call - Labour
The Government has been raising fears about what might happen to its legislative programme if Mr Peters wins this weekend's by-election.
Northland voters go to the polls on Saturday after the sudden departure of National's Mike Sabin.
The Government is currently drafting legislation to change the Resource Management Act. If it loses the by-election, it will need more support to pass it as both Peter Dunne and the Maori Party have reservations about changing the act.
Environment Minister Nick Smith said he did not relish the prospect of having to negotiate with Mr Peters for support.
"I worked with him in the '90s, he is hard work and unpredictable and there is no question that if Winston Peters wins that Northland by-election, resource management reform will be more difficult."
Finance Minister Bill English said, if Mr Peters won, his party would have the numbers to pass a bill prohibiting New Zealand from entering international agreements that included provision for investor-state dispute settlement.
He said that could have serious implications for the newly-signed Korean FTA.
"We're not scaremongering, it's just a fact. New Zealand First has a piece of legislation drawn out of the ballot, which would certainly undermine that agreement."
But Labour leader Andrew Little said that was rubbish.
"The Korean deal, as I understood it, was signed yesterday so I don't think that's going to be off the table any time soon," he said.
"National is desperate about whipping up concern Winston Peters winning in Northland this weekend."
Labour has already said it supports the deal and will vote for the legislation necessary to put it into effect.
Mr Little said the by-election was too close to call between Mr Peters and National's Mark Osbourne.