OTTAWA - Internal documents say the first tranche of spending in the Liberal government's infrastructure program may take three years longer than expected to complete.

The Liberals had originally hoped to have cities and provinces complete $5.4 billion in transit and water system work by this March, but quickly realized that more time was needed.

A "secret" fall briefing note to Infrastructure Minister Amarjeet Sohi, obtained by The Canadian Press through the Access to Information Act, says delays hampered a large number of construction projects, requiring the deadline to be extended to March 2021.

Sohi agreed to a blanket deadline extension to March 2020, turning what was to be a two-year stimulus program into a four-year plan.

He says the decision to grant extra time to 2020, instead of 2021, was based on the expected cash flow for projects and the ability for construction companies to handle all the extra work.

Federal and provincial officials say the lessons learned from the first phase of the program will be used in designing the second phase.