The City of Ottawa has formally asked the federal and provincial governments to commit funding for light rail transit.

Mayor Larry O'Brien has sent letters to both the federal transport minister and Ontario infrastructure minister, asking for their financial support in Phase One of the project.

Phase One, including a downtown tunnel and light rail from Blair Road to Tunney's Pasture, is expected to cost $1.8 billion.

The price tag for the entire Rapid Transit Network is pegged at $3.2 billion with all three levels of government potentially splitting the bill.