Winston Peters doubles down on promise to be first into Pike River mine

Deputy Prime Minister Winston Peters is sticking by his promise to be the first person to re-enter the Pike River mine drift.

Mr Peters first made the promise in front of Pike River families in December 2016, saying: "I'm that confident on the expert advice that you have, that I'm offering to be on the first party back in."

During the post-Cabinet news conference on Monday afternoon, he reaffirmed the pledge.  

"I made that statement a long time, before anybody wanted to enter the mine because I do have an experience of mining or working underground... so it's nothing new in terms of danger," he said.

"The fences being put up by the previous Government were without any validity whatsoever - that's why I made this statement, because I believe it to be true."

Mr Peters said former WorkSafe chief mines inspector Tony Forster, who he says "has a marvellous background and was probably the most experienced person at the time", agrees.

Asked whether it was responsible for him to be first in the mine, he said he did not see any issue.

Earlier on Monday, Pike River Minister Andrew Little said he's "pretty confident" that a safe re-entry of the mine will be achieved by the end of the year.

Police have not ruled out new criminal charges being laid based on any new evidence that emerges if the re-entry takes place.

It's been almost eight years since an explosion at the mine trapped and killed 29 men.