The Labour Party is calling for submissions on the spying powers of the Security Intelligence Service to be heard in public.

Prime Minister John Key has defended the decision to hear submissions on SIS Amendment bill in private, but this morning Labour leader Phil Goff challenged the decision.

"What I disagree very strongly with the Prime Minister on is that the submissions on the SIS bill can't be heard in public. Of course they can be heard in public," Mr Goff said.

"The deliberation and the consideration - that's normally heard in private in select committees anyway. But what people have to say about the bill, that should be open to the public to follow."

He said the committee, which he sits on, could hear material in private if the submission had sensitive material, but they should otherwise be held in open sessions.

Prime Minister John Key said the committee would meet tonight to discuss it, but he still felt that submissions should be heard in private.

Written submissions to the committee can be released if there is nothing in them that could compromise national security, he said.

Submissions will be heard by parliament's intelligence and security committee, which Mr Key chairs.

The committee will report to the House, which will then be a public document.

The legislation that sets up the committee says that its proceedings shall be held in private unless the members unanimously decide otherwise. The committee decides who can be present at the hearings.

Mr Key said hearings were kept private when the committee considered the Government Communications Security Bureau Act under the previous Labour-led Government.

"Unless there is unanimous support, [the bill] is heard in private. It's always been heard in private. There's nothing new there," Mr Key said.