Water Safety New Zealand is disappointed that a bill before Parliament would mean spa pools and hot tubs do not have to be separately fenced.
A select committee considering the legislation has, by majority, recommended it be passed, with Labour and the Greens in opposition.
Water Safety says the committee has favoured cutting compliance costs over children's safety.
But the chair of the committee, National's Scott Simpson, rejects that.
"The committee has given a very careful consideration to every aspect of the bill.
"There was a range of sometimes quite emotional presentations in terms of the submissions and the committee had to find a balance between what was practical and realistic versus what was sometimes the quite prescriptive positions that some submitters wanted us to take."