Prime Minister John Key has indicated the Government will adopt a Green Party bill to change the way referendum questions are set.

Green MP Sue Bradford has drafted a bill to allow questions in Citizens' Initiated Referendum to be set more clearly and has asked the Government to adopt it to ensure it becomes law.

Yesterday Mr Key stopped just short of giving an absolute commitment.

Asked if the Government would pick up the bill, he said: "We are. Well we're in discussions with the Green Party about that but I see some real merit in it.

"I'm not saying holus-bolus [all at once] we're going to pick it up, but we'll have a look."

Ms Bradford's bill was sparked by the smacking referendum question, which Mr Key and Labour leader Phil Goff have described as too ambiguous for the referendum results to have any real weight.

Yesterday Mr Key backpeddled slightly from his initial statements about the importance of the referendum, saying he would not necessarily "totally ignore the referendum".

"My view has always been if there was a substantial vote one way or the other that should send a message to Parliament to have the resolve to change the legislation if it doesn't work, so I wouldn't fully accept the view that there is no message there."

He has previously said the question was too ambiguous to draw any conclusions from and he would not change the law unless he saw evidence it was not working as intended.

However, he repeated his criticisms of the question, describing it as "pretty weird" and saying it "could have been written by Dr Seuss - this isn't Green Eggs and Ham, this is yes means no and no means yes, but we're all meant to understand what the referendum means. I think it's ridiculous myself."

He said adopting Ms Bradford's bill would be too late to change that referendum question.

"But in the future we want to get to a point where if we are going to hold a citizens' initiated referendum at a substantial cost to the public - and let's be honest this is $9 million."

He said the purpose of the referendum was so the public could understand it and "we as politicians can take something out of it".

Clarifying the rules would ensure a "sensible outcome". While citizens should have a mechanism for forcing a referendum, "from that point it is in the hands of the politicians. But I always think if politicians don't listen to the public, eventually they will have a problem."

Ms Bradford has said she was willing to discuss changes to the bill to ensure it was effective. If the Government does not adopt it, she intends to put it in the ballot for members' bills in a fortnight.