The government should stump up $800,000 to help buy a private beach in the Abel Tasman National Park, the Labour Party says.
A crowdfunding campaign to raise $2 million to buy the land at Awaroa and secure public access has received pledges of about $1.27 million.
Labour Party leader Andrew Little said the government should follow the lead of the donors, and pay what was left of the purchase price.
"It's time for the government to show a real faith in New Zealanders, especially in Waitangi weekend when we celebrate our national identity, to step up and say, 'we'll meet the balance, and we'll make sure that this is a beach now that is accessible to the public, for now and forever."
He said there was a risk government investment would drive up the price but hoped the vendor would act in good faith and not bump up the cost.
Christchurch businessman Duane Major and his brother-in-law are behind the fund-raising campaign which runs until 15 February.
Mr Major said that though central government contribution would be welcome, he would rather see the money raised entirely by the public.
"People could raise it sooner, actually, and that speed with which we can raise that money will make a huge difference to how we arrange a tender, and arrange a whole bunch of things.
"That would be Plan A and always was Plan A - just reviving that get up and go spirit."
He said the campaign needed more than $100,000 a day in donations to reach its goal.
Conservation Minister Maggie Barry has previously hinted at the Crown lending a hand to fund the purchase.
Last week she told RNZ that officials were looking at what funds might be available, but said she was wary of the potential for the price being driven higher by the Crown showing an interest.