An attempt by an Opposition MP to change the rules around national superannuation has led to a rowdy debate in Parliament.
NZ First's Denis O'Rourke's member's Bill would pay the pension on a pro rata basis, based on the length of time a person had lived in New Zealand between the ages of 20 and 65.
Launching the first reading debate last night, he said an immigrant who had lived in New Zealand for 10 years was entitled to the full pension.
"Ours is the most generous pensions system in the world," Mr O'Rourke said.
"We are priming a time bomb for the future... many young New Zealanders already don't believe national super will be around when they retire."
He warned national super wasn't going to be sustainable.
"There's the possibility of a tsunami of Kiwis returning to retire on 100 percent national super, after working overseas and paying taxes overseas for many years."
The Bill would disregard two months overseas travel a year and an aggregate five years away between the ages of 20 and 65.
It would also allow people to keep overseas pensions if they were entitled to receive one.
National's David Bennett said the Bill was "one of the most tragic" that had been brought to Parliament.
"It's an attempt by a party with no moral compass to differentiate between New Zealanders... they're saying if you weren't born here you aren't a true New Zealander," he said.
"It's a disgrace that we even have to debate it."
Amid noisy interjections from NZ First MPs, he said the party wasn't fit to be in Parliament.
Labour's Grant Robertson said Mr Bennett was a disgrace.
"The Government doesn't want to have a conversation with New Zealanders about the most important part of our social welfare system," he said.
"If we want to make sure there is national super for generations to come, we have to have that conversation."
Mr Robertson said Labour had problems with the Bill but would support it on its first reading so it could go to a select committee for public submissions.
The Greens took the same stance, but ACT leader David Seymour said the Bill was unworkable and unenforceable.
It was defeated on its first reading by 61 votes to 60.
National, ACT and United Future opposed it.
NZ First, Labour, the Greens and the Maori Party supported it.