ACT Party leader David Seymour has called for New Zealand First leader Winston Peters to release his original form applying for the pension, after it was revealed he was receiving more than he was entitled to for seven years.
Mr Peters had been claiming the single person's pension, rather than that of someone in a couple, since 2010, until the blunder was discovered this July as his partner applied for her pension.
- Lloyd Burr: Why did so many people need to know about Peters' pension saga?
- Winston Peters accuses National of 'filth and dirt'
Mr Peters has maintained his partner was with him when he signed up and he's not sure how the mistake happened.
Now Mr Seymour has called for an investigation into a leak which saw the information passed on to a Newshub reporter.
"I know that secret files don't get out of the Government's computers and into journalists' inboxes by mistake," Mr Seymour said at the ASB Great Debate in Queenstown on Wednesday night.
"One of the best things we could do is Winston, mate, just give them the file, so we can know it really was just a minor administrative error and we can all move on."
It's since emerged a number of National Party members were told about Mr Peters' pension problems, as part of the 'No Surprises' policy. National finance spokesperson Steven Joyce, also at the debate, "categorically den[ied]" that a National member was involved in the leak.
Mr Peters argued they shouldn't have been told at all, as it wasn't relevant to the Government.
'Chihuahuas' scrap at finance debate
It wasn't the only clash between Mr Seymour and Mr Peters during the debate, which saw another party representative joke the two were "like a couple of Chihuahuas".
At one point Mr Peters scornfully pointed out Mr Seymour was talking big talk considering what his party was polling - 0.6 percent, according to the latest Newshub-Reid Research poll - and called him "a National party puppet".
At another, Mr Seymour criticised Mr Peters' many "bottom line", his rules to working in a coalition with any party.
"He's got more bottom lines than a 100-year-old elephant," Mr Seymour cracked.
But Mr Peters was the one with the final laugh: "Mr Seymour, let me tell you: I will be there after the election and you won't be."