"The publicly stated opening date of the end of 2016 and the approved budget are not achievable," says a TTC report that will come to the TTC board at its meeting next week.
The report calls for a complete "reset" of the project, and calls for a number of options to speed it forward, including the use of a third-party-project manager to complete the project by December 2017.
The report calls for the extra $150 million to be shared by the municipalities of Toronto ($90 million) and York Region ($60 million).
The project will extend the subway by six stops north from its current terminus at Downsview station to the Vaughan Metropolitan Centre.
The project, originally budgeted at $2.6 billion, has been hindered by cost overruns and problems with contractors.