After repeatedly missing deadlines for scheduled deliveries of Toronto's new streetcar fleet, Bombardier's difficulties manufacturing the new vehicles could continue, TTC staff say in a report released Wednesday.

"Based on supporting documentation received to-date ... staff believe that there is a risk that Bombardier may not be able to meet its revised delivery schedule as submitted on May 18, 2016," the report says.

Moreover, TTC staff say "there is a risk that Bombardier may not meet the revised delivery schedule for contract completion of 204 new streetcars by 2019."

Staff are basing that opinion on their assessment of the Montreal-based company's production readiness at its plants in Thunder Bay, Ont., Quebec and Mexico. In addition, they say Bombardier has not submitted a detailed project schedule (DPS) since January 2016 for the full length of the project.

"TTC continues to request an updated DPS in order to understand and plan for the impact of these deliveries on TTC resources. Bombardier has advised that a DPS is forthcoming," the report says.

The TTC is expecting the delivery of 76 cars in 2018 and 58 cars in 2019. Staff say if Bombardier wants to meet that schedule it "will require an average delivery rate of approximately one car every 3.3 days and 4.4 days respectively."

The TTC board will meet on Tuesday to discuss the staff report.

Since the city of Toronto awarded Bombardier the contract for the Flexity streetcars in 2009, the company has repeatedly missed deadlines for delivery. Right now, there are more than 20 of the state-of-the-art vehicles on the rails in Toronto. Under the revised schedule, the TTC was supposed to have 30 in service by the end of this year.

In October of last year, the TTC board voted to sue the manufacturer over the production delays.

In the past, Bombardier has blamed the delays on faulty parts from its supplier in Mexico, labour trouble, the intricate nature of the new streetcars and staff changes.