Sinn Féin says the HSE's stated aim of bringing down scoliosis surgery wait times to four months is unlikely to be met by the end of the year.
The Children's Ombudsman published a report earlier saying no child should have to wait longer than four months.
There are currently almost 200 children waiting for the surgery for over 18 months.
The party's Health spokesperson Louise O'Reilly isn't convinced that a new operating theatre due to open in Crumlin Children's Hospital next month will have the required staff.
The Ombudsman for Children has criticised the waiting time for treatment for children with scoliosis.
She was speaking at the launch of the 'Waiting on Scoliosis treatment; A children’s rights issue' report, which found that there are almost 200 children in Ireland waiting over 18 months for surgery.
The Government has committed to bringing wait times down to four months by the end of the year, a target the Ombudsman, Niall Muldoon, said is very ambitious.
“It’ll be a huge ask to turn that around, but again, I’m quite happy to give them that opportunity to do that, and we will follow up as quickly as possible if that doesn’t happen.”
Minister for Health, Simon Harris said that he welcomes the publication of the report.
Speaking today the Minister said: "This report rightly highlights the need for significant improvements to be achieved in terms of waiting times for scoliosis procedures for children and teenagers in Ireland."
"This absolutely is a priority for me, for the Government and for the HSE this year. I welcome the fact that the HSE has committed that no child will wait longer than four months for such a procedure by the end of the year. This would bring Ireland in line with waiting times in the NHS in the U.K."
"A range of measures will be used to get to this target including additional theatre capacity in Crumlin from April."
The Minister will be meeting again with scoliosis advocacy groups in the coming weeks to update them on progress.
Labour spokesperson on Health, Alan Kelly TD, criticised the Government for its failure to address the lengthy waiting times.
Commenting on the report, Deputy Kelly said: “It is simply unacceptable that any child in this country should have to wait in pain for over a year for potentially life-changing surgery.
“At this point it has become a national disgrace that we cannot solve this ongoing crisis that is causing such pain and anguish for children and their parents.
“We saw in the recent Living on the List programme how the condition of a 13-year-old girl with scoliosis had significantly worsened over a two-year-period, putting her and her family through significant pain and anxiety.
"At the time, I said we should set a six-month deadline and fast-track treatment for the more than 200 children on the waiting list, which would at least give the public some confidence that we can solve these problems.
“As the Ombudsman has said, the delayed treatment times are actually impacting on children's rights.
“So yet again I'm calling for concrete action to cut the waiting times for scoliosis surgery to alleviate the suffering of children with this condition."
The Children's Ombudsman says the Government must deliver on its promises when it comes to children on waiting lists for Scoliosis treatments.
The issue was highlighted by RTÉ Investigates documentary Living on The List, and later by the appearance of Megan Halvey-Ryan on the Late Late Show.
A new report out today says the condition, in which a person's spine has curved, has become a children's rights issue in Ireland.
Dr Niall Muldoon said the current situation cannot continue and they have issued a series of recommendations.
Speaking ahead of the launch of the Ombudsman for Children’s Office report, 'Waiting on Scoliosis treatment; A children’s rights issue', he said: “Ongoing delays and the failure by Government to adequately address the issue of access to Scoliosis treatment is impacting on the rights of children and young people in Ireland.
“Every child in Ireland has a right to the highest attainable standard of health. At present that right is not being respected for children and young people with Scoliosis and crisis managing has not resolved the issue.
“Due to their age and stage of development, young people with Scoliosis are suffering severe physical and psychological effects as a result of the delays they experience. This should not be acceptable in Ireland 2017.
“The testimonies of three young people included in this report, make for powerful and chilling reading."
Dr Muldoon continued: “No child with scoliosis should have to wait in excess of 4 months from when the need for surgery is clinically determined. This is in line with recent Government commitments and complies with international best practice.
“Long-term planning and strategic thinking is needed to address this issue. We need a clear picture of existing capacity and the availability of human, financial, and technical resources.
“Child-specific waiting lists should be published for all healthcare services in Ireland. Targets for maximum waiting times for out-patient appointments should be established, and reports which monitor these targets should be published quarterly.