Individual and big submitters like district councils are being given until 30 June to make further submissions to the Te Tai o Poutini Plan.
It means the start time for formal hearings in August is now likely to be even later in the year.
The TTPP Committee on Wednesday considered a recommendation from plan staff to extend the timeframe for further submissions until 16 June but then pushed it out further, to 30 June.
It heard that staff had fielded several inquiries relating to errors in the summary of the original submissions - mainly from the region's three district councils.
Acting plan manager Rachel Vaughan said these were largely around topographical and formatting details and needed to be rectified, although they did not affect the substantive content of the original submissions.
A corrected version of the summary was due to be sent out to submitters by yesterday.
But several consultants representing submitters felt the errors were "significant" and had asked for the whole summary to be reviewed.
Vaughan said errors in the submissions summary were not unprecedented given the scale of what the plan sought to achieve, but very few would "put us at legal risk".
At the same time there had been several requests to extend the submissions period.
Up to half a dozen people or organisations including the district councils were worried at "the sheer number" of submissions they had to get through in order to form a view and meet the further submissions timeframe, which was due to end today.
Buller Mayor Jamie Cleine noted the complexities of council staff time faced with going back to "square one" after they had detected minor mistakes in the submissions summary, released in the middle of last month.
From the point of view of public perception "and trust in the process" it was important for the committee to draw a line and put out a new summary document with an appropriate timeframe for people to absorb it, Cleine said.
Vaughan pointed out that in any event, further submissions would refer back to the detail of the original submission in each case when it came to the hearing stage.
Councillor Graeme Neylon of Buller asked if any of the errors were compounding.
Vaughan said most of the detected errors had been "annoying."
"They are not so extensive that it means all the work has to be redone but it will be more work to reload to the website."
Te Runanga o Makaawhio chairman Paul Madgwick said it was inevitable that mistakes would "creep in".
In itself the plan had been a massive undertaking.
"At least, we have to give every opportunity for the public to have a fair say and get their heads around it," he said.
"I'm really comfortable with the extension."
The supporting report to the committee noted the large number of submission points covered in the summary - more than 15,000.
The committee had previously agreed in April to extend the further submission period to 20 working days, until 26 May.
Local Democracy Reporting is Public Interest Journalism funded through NZ On Air
* Disclosure: Te Runanga o Makaawhio chairman Paul Madgwick is also the editor of the Greymouth Star. He took no part in the commissioning, writing or editing of this LDR story.