Labour's backing a campaign to slash gift card expiry dates.
The party's supporting Consumer NZ's Drop the Dates effort, which launched before Christmas.
Consumer affairs spokesman Michael Wood says retailers need to do "the right thing".
"We've got a lot of New Zealanders who received gift cards over Christmas," the new Mt Roskill MP told Newshub on Saturday. "People spent good money on those in good faith, and there's actually no good reason why the value should just suddenly disappear overnight at some arbitrary date after the retailer has received the money."
Countdown, Kathmandu, and Noel Leeming have already agreed to get rid of gift card expiry dates.
According to Consumer NZ, more than half expire after 12 months. Ticketek was deemed the "meanest", with vouchers needing to be used within six months before they become worthless.
"It's hard to find a good reason why retailers need to impose expiry dates on the cards," Consumer said in December.
"Most Canadian provinces have banned expiry dates. Ireland is planning to follow. Gift cards in the US are required to have an expiry date of at least five years."
It's estimated around 20 percent of gift cards aren't redeemed in full - the retailer getting to keep the money in exchange for nothing.
Mr Wood says 2017 is the year for all retailers to make the change, and he'll be writing to big retail chains which don't.
"It's good time for retailers to have a little bit of a think about this."