An application to build the Dublin Metrolink rail line is unlikely to be made until 2020.
It is down to delays in determining a revised route for the line.
Transport authorities had been due to announce the redesigned route last August, but that was pushed back to November.
It was further delayed to allow time to design an extension of the underground section past Ranelagh.
However, the Irish Times reports that the revised plans will not be ready until February at the earliest, with the planning application to An Bord Pleanála pushed out to 2020.
Construction of the line was due to start in 2021 for completion in 2027
It is not yet known if this schedule will be affected.
A spokesperson for the National Transport Authority said there are a number of public concerns and engineering elements which it is working to resolve.