Prime Minister John Key says he's "deeply disappointed" about the leak of a confidential cabinet document outlining the government's position on ministry restructuring.

Labour MP Phil Goff last week released the paper, prepared by a cabinet committee, before the full cabinet had discussed it.

It revealed 146 jobs were going to be axed in the Ministry of Foreign Affairs and Trade (MFAT), and that the Stockholm embassy would be closed.

Mr Key is suggesting the document was handed over by someone who is going to lose their job.

"I was deeply disappointed because these are people charged with diplomacy and upholding the highest standards," he told reporters.

"But I think an awful lot of people in MFAT, whatever they think of the outcome or the process, will be ashamed of their organisation because of that."

Mr Key has previously ruled out an inquiry, saying they hardly ever succeed in finding culprits.

"I understand about 20 people had access to that document ... some people are going to lose their jobs and it's eminently possible that the person who leaked it is in that category."