The National Government's $212 million plan to fast-track regional road projects using asset sales cash is not backed by a strong economic case, documents released under the Official Information Act show.
Opposition MPs have labelled the projects a cynical bid to buy votes.
The regional road and bridge projects, many of them in Cabinet Ministers' electorates, were announced at the National Party conference in late June.
Documents released to Labour strategist and blogger Rob Salmond by Transport Minister Gerry Brownlee's office show most of the 14 projects have a benefit to cost ratio of less than four with five in the range of 0 to 2.
Green Party transport spokeswoman Julie Anne Genter said that meant they were relatively uneconomic compared to many other projects awaiting funding under the New Zealand Land Transport Agency's plans.
However National is sidestepping NZTA funding constraints by using cash raised from selling part shares in power companies and Air NZ to pay for its favoured projects.
Ms Genter said the Government was promoting road projects "on the basis of where they'll get the most votes rather than an objective assessment of what's going to best for the economy and for the transport system".
Labour transport spokesman Phil Twyford said the Government had starved regional New Zealand of funding for roading projects over the last six year unless they were deemed as "roads of national significance".
"This $212 million package of projects is basically an election year lolly scramble and I would say that it's cynical in the extreme.
"These projects should be funded on the basis of their economic value and their regional priority not as an exercise in vote buying."
Mr Twyford said some of the projects were good ones but others were not, such as the Nelson Southern Link had already been rejected by the Environment Court, " now it's being brought back clearly because of (Cabinet Minister and Nelson MP) Nick Smith's lobbying".
Transport Minister Gerry Brownlee said the Government believed the roads were worth doing despite the fact they had been "basically on the never never" in terms of the NZTA's programme.
"They're roads communities have identified through their MPs and through their correspondence with the Government, and yes they don't fit inside the big plan and that's why we've funded them separately, so if people want them, we're there to deliver them. If they don't want them, vote Labour."