David Seymour wants explanation after Christopher Luxon told him he'd investigate leak - and then didn't

Cracks are appearing in the Coalition over Christopher Luxon's apparent captain's call not to investigate a Cabinet leak.    

David Seymour asked for an investigation into a leak about referendums on Māori wards - and was assured by the Prime Minister he would get one.   

But Luxon's now told Newshub said he won't bother with an investigation because he said he's got better things to do. Seymour now wants an explanation.   

The three-way Coalition was built on trust and talking - a lot of talking during negotiations.    

It was all smiles when they pulled it together but the grins have turned to grimaces - the Government's got a leak problem.    

"Leaking is corrosive to a Cabinet and a Government and we should be making sure that if it happens, we've investigated it," ACT Party leader Seymour said on Tuesday.   

It began with the leak of a Cabinet paper to Newshub just a week after the Government was sworn in. An investigation was launched and it was pinned on a public servant.   

Other leaks have also resulted in probes.   

But the latest is to pass by without an inquiry. The Prime Minister isn't interested in finding out who leaked confidential Cabinet intel.   

Asked if he had investigated the leak out of Cabinet a week ago, Luxon said: "No, not particularly."   

Just before Easter, TVNZ reported it had received a Cabinet leak detailing decisions around holding referendums on Māori Wards for local councils.   

Asked by Newshub if anyone had asked him to investigate that, Luxon said on Tuesday: "No, again we don't talk about what goes on in Cabinet."   

The minister most affected by the leak - Seymour - revealed to Newshub he did ask for a probe.  

"There was a leak recently, I raised it with the Prime Minister and I'm very happy with his response - that he's dealing with it," Seymour said.  

But dealing with it appears to have meant leaving it be.    

"I'd just say to you, from our point of view, it was an imminent decision that was being made it was well understood, well signposted and we're moving on," Luxon said.    

When Newshub told Seymour Luxon had said he wasn't investigating, Seymour replied: "He certainly told me he intended to do that and I expect to see him act on it very soon."

Luxon initially insinuated this leak also came from the public service but TVNZ explicitly said it came from closer quarters.   

Asked what evidence he had that the leak came from the public service, Luxon said: "I don't know, I don't know."   

He then said he had "more important things to do".    

Seymour said he "raised it with" with Luxon.  

"He said, 'Leave it with me' and, for me, that's good enough. If he's now saying something different, that's going to need a further conversation."