More than 85 per cent of calls to PlunketLine went unanswered last month but Health Minister Annette King says she is confident that figure will improve.
National Party associate health spokeswoman Katherine Rich says Ms King gave a public assurance the service would be up to scratch by the end
of this month.
But figures for May showed that of the 35,610 calls to PlunketLine, 87.4 per cent were not answered. Only 4485 calls were handled.
PlunketLine is being merged into Healthline, a process expected to be complete by the end of the month.
The 24-hour, seven-day-a-week service will be staffed by registered nurses able to give advice based on symptoms and refer people to the nearest after-hours medical service.
It will cost $10 million a year to run.
Ms Rich said since the amalgamation of the two free-calling services was announced, PlunketLine appeared to have become "the poor cousin", with large numbers of parents finding no help at the end of the line.
In contrast, Healthline had received 13,032 calls in May and only 4.9 per cent went unanswered.
"Before the merger the minister was shocked that 30 per cent of calls went unanswered. Now, when nearly nine out of 10 calls are unanswered, she's taken her phone off the hook," Ms Rich said.
Ms King said she was not happy with the figures but Ms Rich was "making assumptions based on politics". It was not possible to make comparisons with figures before the merger as PlunketLine did not have the technology to accurately record call numbers in the same way.
"The Government wants to see a high success rate from the merger and I am sure both organisations will continue to work towards that enthusiastically," the minister said.
In March, Ms King said the organisation's contract required that by the end of June, 80 per cent of Healthline/PlunketLine calls had to be answered within 20 seconds.
Last weekend, 90 per cent of the 706 calls to Healthline were answered and she wanted to see that success rate replicated by PlunketLine.
