Updated 9.24am: Winston Peters is on the attack over the closing down of a health centre the government says doesn't exist.

The New Zealand First leader says the Wellsford community health office is under threat, but the government's waiting a few weeks before its closed.

"I kind of think that this is linked to the fact that they don't want people upset in the by-election, and they're going to close it afterwards."

Health Minister Jonathan Coleman says there is no Wellsford community health office.

"The best advice that I've had is that there's no facility in Wellsford that is closing, and that is what my officials have told me."

There is a public health nurse operating out of her own office in Wellsford.

The local DHB's deputy director of funding, Tim Wood, says she's not going anywhere.

"The DHB has no intention to discontinue their role, and they will be based in Wellsford on an ongoing basis."

Tim Wood says the DHB is looking into extending its services into Wellsford.

Meanwhile National's telling Northlanders to think about what they're in for if they vote for Winston Peters.

It comes as the Prime Minister announcing he's cutting his trip to South Korea and Japan short to get back in time for the last push for the seat.

Deputy Prime Minister Bill English says Northland voters need to decide if Winston Peters will be able to do anything for them.

He says they might have a party on the novelty of voting for Mr Peters, but then they have to deal with the hangover of no effective representation.

Bill English says Northland needs a local MP who is living and breathing the issues there.

Ministerial visits

The Prime Minister's adamant his party's following all the rules when it comes to the Northland by-election.

In the past two weeks the electorate's been a frequent visiting spot for cabinet ministers and MPs as the Government campaigns hard to hold on to the seat.

It also coincides with Parliament sitting.

But John Key says the rules are clear for MPs and Ministers about when they can claim expenses for transport and accommodation.

He says for travel and accommodation National MPs are either being billeted in the electorate, or are paying their own way.