Prime Minister John Key says ten bridges in Northland will be rebuilt regardless of which party wins the seat's by-election.
As the by-election campaign heats up, the Government has announced it will replace ten single-lane bridges on Northland's Twin Coast Highway over the next six years, at a cost of up to $69 million.
Opposition parties have said the announcement is cynical pork-barrel politics and showed National was panicking about losing the by-election.
But Mr Key said the Government was committed to improving roading in Northland.
"We've been very committed to the roading projects in Northland. We've spent three quarters of a billion dollars there in the last seven years, that's 40 percent more than labour spent in the time that they were in office.
"We're very committed to Puhoi to Wellsford, so yes, these bridges need upgrading and they will be."
Transport Minister Simon Bridges said replacement of the bridges was the logical next step from the development of the Puhoi to Wellsford Road of National Significance, and the increased visitor numbers that will follow.
Mr Bridges said funding for the projects would primarily come from the National Land Transport Fund.
He said the National-led Government had invested over $750 million in state highway and local roading projects across Northland over the last seven years, 40 percent more than the previous government.
National's candidate Mark Osborne said one of the important benefits of the programme would be improved safety on Northland's highways.
"One night last winter, I came across a head-on smash on the Kaeo Bridge when I was driving north. Luckily no one was seriously injured in that crash but there have been a number of serious crashes on the bridge over the years and it really is a ticking time-bomb."
Mr Osborne said he had campaigned for the bridge replacements during the candidate selection process and the National leadership has endorsed his approach.
Labour leader Andrew Little said National was playing cynical politics by making the announcement during the Northland by-election campaign.
"There's no question that an announcement about roading upgrades and new bridges in the heart of the by-election is cynical and it is pork-barrelling.
"There are plenty of one-lane bridges in Northland that haven't had the attention of the Government in the whole time they've been represented by a National Party MP."
New Zealand First leader and Northland candidate Winston Peters said the expected cost range of between $32 million and $69 million showed how quickly stitched up the announcement was.
"This is extremely haphazard, unfocused, unresearched and it's being announced in a panic. That huge difference between those figures is something we cannot expect is supported by in-depth research."
Mr Bridges said despite the by-election National would continue with significant investment in the region.
"There's no question that the decision to do these bridges [is] in the context of a by-election, but over the last six years, we've demonstrated deep commitment to Northland.
"We have invested a lot [in the region] and regardless of the by-election we were always going to continue to invest very significantly [in Northland]."
Regional Transport Committee chair John Bain said the bridges had been on Northland's to-do list for some time, but he wasn't expecting the funding quite so soon.
"We actually had meetings last week with the NZTA last week, and we had put the public submissions together; we had been fairly strong with our wishes, so obviously the message hasn't fallen on deaf ears, which is very pleasing."
Mr Bain said if the Government was now keen to fix Northland's roading problems, it might next like to consider building a tunnel through the Brynderwyn.
- Taipa Bridge on State Highway 10
- Kaeo River Bridge on State Highway 10
- Waihou River (Rangiahua) Bridge on State Highway 1N
- Tirohanga Stream Bridge on State Highway 11
- Taheke Bridge on State Highway 12
- Waimamaku River (Hallahans) Bridge on State Highway 12
- Waimamaku River (Lowes) Bridge on State Highway 12
- Darby and Joan Kauri Bridge on State Highway 12
- Andersons Bridge on State Highway 12
- Matakohe River (Hardies) Bridge on State Highway 12
Advance voting starts on Wednesday and the by-election will be held on Saturday 28 March.