The National Capital Commission is demanding the City of Ottawa bury the entire stretch of its western light rail extension that would run alongside the Sir John A. MacDonald Parkway.

The city wants to use a 1.2 kilometre stretch of NCC land for the future westward expansion of light rail, with a plan to bury a portion of the line between Skead Street and Cleary Station earlier this month.

The NCC’s board unanimously approved a motion on Friday calling for "unimpeded, continuous access" to the Parkway corridor and Ottawa River shoreline.

"The city’s last proposal was 700 metres are covered, why not cover the whole thing?" said board chair Russell Mills.

"We’ve never seen a plan like that, the board feels strongly it should see a plan from the city to do that. This land belongs to all the people of Canada, we have to be very careful about how we give it up for local use."

The NCC is asking the city for a revised plan before September, when it will approve its transportation master plan.

The city has said the deeper it digs underground, the more expensive the expansion project would become.

A look at the city's preferred route for expanding the LRT to Ottawa's west end, and how it fits with the O-Train and planned Confederation Line.

View LRT western expansion in a larger map