The UMR Research survey by Auckland University found that 67% of respondents either strongly or somewhat agreed that a tax should be imposed.
The data reinforce the almost identical results of a Colmar Brunton poll conducted in April 2016.
Support was evenly split across all income levels. Those expected to be most opposed to a tax—the lowest income group which consumes the most sugary drinks—were most strongly in favour.
Despite the results of these surveys, health minister Jonathan Coleman said the government's position on a sugar tax hadn't changed.
"It's not something we're actively considering. We are continuing to keep a watching brief on the emerging evidence and practice,” he said, adding that there had been no evidence that a tax on sugar would have an impact on obesity rates.
The opposition Labour party is preparing its own sugar tax policy, however.