NZ First leader Winston Peters is the latest politician to voice concerns about the timing of the royal visit, saying the "misuse of the royal family'' was "disdainful''.
Earlier today, Labour leader David Cunliffe took a dig at the Prime Minister John Key over the level of his involvement in the royal tour and said any visit to the White House in an election year would be "pre-election PR from the Prime Minister."
Mr Cunliffe said Labour welcomed the royals and did not want to play politics with the visit. However, he said such visits should be as "even handed as possible between the Government and Opposition, and also that it is well enough spaced from the election."
His comments were backed by Mr Peters, who said it was "seriously unfortunate" that the visit should happen in an election year.
"We don't want to make a controversy of it, but [Mr Key] could very quickly slide into an abuse of the institution and I hope that doesn't happen.''
He said most New Zealanders were pleased to see the royals, but it would have been better if they had visited last year or next year.
"They head the Commonwealth, they still head this country for the meantime and mixing politics with that institution is thoroughly bad. I find the misuse of this family slightly disdainful.''
Mr Key said he did not believe there was electoral advantage to be gained from the visit. "I don't think it's particularly a time for politics. I don't anyone is going to vote National, Labour or or any other political party because we're seen snapped next to the royals while they're in New Zealand.''
He said there were very few things he was doing that Mr Cunliffe was not also attending.
"We spent a long time when Helen Clark was Prime Minister and we didn't get the same access that the Prime Minister of the day gets. That's the point.''
He said the same point applied to a possible White House visit.
"If it's just a matter of me wanting to have a photograph of me wanting to have a photograph with Barack Obama well I can show him the shots I've got off the golf course. It's not like people don't know that I know the President of the United States.
"But again, I just don't think anyone is going to vote for National because they see a photo of me next to some other famous world leader. They vote on the economy, law and order, health and education. As soon as David Cunliffe starts talking about that and not rubbish he might do a bit better.''
If you're out spotting the royals, we want your snaps. Share them with us, including details of where you took the photo, here.
Mr Cunliffe said he would leave it to the public to decide whether it was even-handed, but when prompted further said it was not.
"I guess [John Key] likes the camera time. I think the public will watch closely to see how the Prime Minister treats his presence on the tour in an election year so close to the election. Our position is to welcome the tour and I look forward to meeting the Duke and Duchess."
Last month Mr Key also said he was hoping for an invite to the White House this year because it was usual for a Prime Minister to visit once in each electoral cycle.
Mr Cunliffe said that would effectively be a publicity stunt. "I think he is stage managing the calendar of the year as it suits him."
Mr Cunliffe will travel to Blenheim on Thursday for a World War 1 commemorative event as part of the royal visit and has a formal meeting with Prince William on Thursday night before attending the state reception with other MPs. Mr Key has a pared down programme compared to previous visits by Prince William.
However, as well as the same events as Mr Cunliffe, he was at their arrival yesterday, will have a private dinner with them and attend the opening of the new National Cycling Centre of Excellence in Cambridge on Saturday, as well as waving them off at the airport next Wednesday.
Mr Key said yesterday that he would have a limited role in the royal tour and "will not be barnacle." He also said he did not expect it to benefit the National Party's election chances.
Mr Cunliffe said he would largely leave it to the Prince to decide what he wanted to discuss at their formal meeting on Thursday.
"I'd be happy to brief him on our general approach to the election and the issues we think are important, about building a fairer, more decent New Zealand, and including everybody in the opportunities. I'm sure he would agree with that."
He also expected to discuss the economic issues facing New Zealand, such as the balance of payments and current account. Asked if that would be of any interest to the Prince, he said Prince William was "a very well read and substantive person, and a very charming person."
Mr Cunliffe has previously voiced concern about hosting the royals in an election year, saying it allowed for photo opportunities for the Prime Minister.