The government have been warned of planning risks with the chosen location for the National Children's Hospital.

An Taisce has written to Enda Kenny outlining that building the hospital at St. James's without a maternity hospital on site will pose serious risks and that it should be built at the site adjoining the Coombe Hospital.

It is now feared that the hospital will not be completed by 2018 after initial problems at the original site pushed the completion date out by two years from 2016.

Consultant Ophthalmologist at the Mater and Temple Street Hospitals is Professor Michael O'Keeffe. He told the Pat Kenny Show here on Newstalk that there may be many obstacles.

The Minister for Health James Reilly had hoped the project would be completed by 2016 but a planning issue over the original chosen location beside the Mater Hospital means it now will not be complete until 2018.

Health Correspondent with the Irish Times is Paul Cullen. He outlines the risks noted by An Taisce.