Nelson lawyer Rick Farr has put local body amalgamation back on the table, but his timing is questioned by one of the idea's strongest proponents, Nelson MP Nick Smith.

Both mayors are also publicly wondering why the idea has been put forward again so soon after being rejected in a region-wide poll.

The Local Government Commission has confirmed that Mr Farr lodged a proposal last month for the Nelson city and Tasman district councils to amalgamate.

Such a proposal was favoured by Nelson voters but emphatically rejected by Tasman voters in April last year, after then-Nelson mayor Aldo Miccio led a pro-amalgamation push.

Under legislation passed at the end of last year, an individual or group can approach the commission without the need for a petition, and it must then decide whether the proposal merits being taken forward.

Mr Farr told the Nelson Mail yesterday he went ahead after discussions with "a number of local businesspeople" who were concerned that the issue "should not be left where it is".

In a statement he said it was apparent to many that the separation of Nelson and Tasman along a "rather arbitrary line" south of Stoke had no real rationale.

"Many see that the strength of the region would be very much enhanced through amalgamation of the two councils."

With just under 50,000 people in Nelson and a similar number in the Tasman district, amalgamation would move the region from two smaller population bases to "what would be a real force on the national stage", Mr Farr said

However Dr Smith, who has long favoured the amalgamation of the two authorities as being in the best interests of the region, did not know of the new proposal until told by the Mail and said it was premature.

"I remain of the view that the region would be best served by a single district council, but this is all about a good process and getting the detail right." Dr Smith said the commission currently had major proposals for reform in Northland and Hawke's Bay and discussions under way in Thames-Coromandel and Wellington.

"My view was to allow the new law to be applied to those areas before giving further consideration to a Nelson reorganisation."

He said a key deficiency in the earlier proposal was the strength of local representation in communities like Motueka and Golden Bay.

A bill before Parliament allowed for local boards with considerably more powers than the existing community boards. That model was used in Auckland but had not been allowed in the options for Nelson and Tasman.

"I would prefer that legislation went through with those additional options before any new proposal was considered for Nelson and Tasman," he said.

"There's a tough test in the local government reorganisation provisions for the information for a reorganisation - it will be interesting to see whether this proposal meets that test."

It was also news to Nelson mayor Rachel Reese, another amalgamation supporter, and she also said the timing was off.

She respected Mr Farr's right to make an application, but the community had been polled only 18 months ago.

"We are focused at the moment on setting priorities for the next annual and long-term plan.

"I'm conscious that we've got a lot of unfinished business to attend to and we've really got to keep our energies focused on delivering those results."

It was a risk for councils to be distracted by matters that weren't a top priority for residents and ratepayers, Ms Reese said.

Tasman district mayor Richard Kempthorne, who has consistently opposed amalgamation, said he wasn't surprised there was ongoing interest but Mr Farr's timing was questionable, with a decisive rejection of amalgamation 18 months ago.

He hoped and expected that the Local Government Commission would not advance the proposal.

"With new councils into the new term getting on well and chief executives getting on well, there's a lot of progress being made, and that's where I hope our focus can remain."

Commission chief executive Donald Riezebos said there were "a whole lot of tests" in the Local Government Act, mainly around the content of the proposal and the degree of community support.

"The commission is still assessing the proposal from that point of view.

"It's fairly short, about 2 pages, which is a lot shorter than the other ones we've got under the new legislation."

If it decided to take the proposal forward, the commission would give public notice and call for alternatives.

These would then be considered along with the original application "and any other ideas that come up in the mix".

If it opted for some sort of change, it would issue a draft proposal for submissions, then a final proposal.

"At that point a poll will only occur under the new legislation if 10 per cent of the people on the electoral roll in one individual district petition for it, and then the poll itself is a single poll held over the combined area."

This means that unlike under the previous law, an amalgamation poll can go ahead if it gets 10 per cent support from either Nelson or Tasman, rather than requiring both districts to back it.

If the commission did take up the proposal it would be well into next year before the process was completed, Mr Riezebos said.