A Green Party bill requiring lobbyists to register and disclose their meetings with MPs and other public figures is set to pass its first stage after Prime Minister John Key said National was likely to support it.
Mr Key said Green Party MP Holly Walker's member's bill to regulate lobbyists was "worth looking at", as New Zealand was one of the few countries which did not have a disclosure system.
Although National's caucus was yet to consider it, he said it was likely the party would support it, at least through its first reading, so it could be considered by a select committee.
The bill would require paid lobbyists to register and subscribe to a code of ethics set by the Auditor-General. They would also have to reveal which public figures they had met, the topics discussed and some of the methods they used.
Labour will also support the bill, but spokeswoman Clare Curran said it was likely changes would be needed.
The main point of contention was the definition of lobbyist, which the bill defines as people who lobby public officials about laws or policies for the organisation that pays them. It includes businesses, voluntary organisations, charities, trade unions, interest groups and any group of people working toward a similar goal.
Ms Curran said lobbying was a legitimate activity and should be regulated, but there was a concern the bill as it stood captured small, informal groups or individuals who simply raised a matter with their local MPs.
Mark Unsworth, a partner at lobbying firm Saunders Unsworth whose clients include SkyCity, raised a similar concern, saying the bill could cover a Catholic priest in Christchurch who discussed child poverty with local MPs on the side of the road.
Matthew Hooton, a lobbyist with Exceltium, said the bill would need some changes but was fine in principle.
"It's an unregulated industry and in most countries [lobbying] is regulated, so it's probably due for some regulation. It will be interesting to see how often groups like Greenpeace and trade unions meet Labour MPs."
He said there was a risk the level of disclosure would deter MPs from meeting organisations and groups in case they were accused of being influenced.
That would result in ministers relying on their ministries for advice without wider input from those in the sector.
"If ministers feel they can't have those meetings, that would be perverse."
Ms Curran said MPs recognised lobbyists on all sides of a debate had value, regardless of whether they agreed with them or not.
She said the bill could also help address "unfair access" some lobbyists had to politicians, such as the 16 lobbyists who have swipe cards giving them entry to Parliament without going through the usual security checks. Those included Mark Unsworth and Sky TV's Tony O'Brien.
Mr Hooton said the Speaker had given him approval for such a card some years ago but he hadn't bothered to collect it.
The cards have "official" written on them, similar to those issued to public servants visiting Parliament. Mr Hooton believed they should have "lobbyist" on them, but said they were not as advantageous as many believed.
They didn't give access to MPs' offices and appointments were still needed for meetings. However, those with the cards could enter communal areas such as Parliament's cafe.