After a day of lengthy debate on the future of the city's $7-billion transit plan, city council is yet to make a decision on whether they will move forward with the plan or put it on hold.

"It's one of the most critical decisions that I can remember, definitely since we started the new city and even going back in the history of the Ottawa-Carleton region," Coun. Doug Thompson told CTV Ottawa.

If council approves the multi-billion dollar transit plan put forward by city staff, Ottawa residents would one-day have access to a downtown tunnel and light rail from Blair Road in the east to Tunney's Pasture.

The plan, however, is expensive and has many councillors wondering if the city can afford it.

"Today we're entertaining a motion that would double the city's debt," said Coun. Diane Deans.

"I think in these troubled money times in the world, we have to keep our eye on the bottom line and make sure that we're not creating a big debt, an unaffordable debt, for our taxpayers."

Ontario Municipal Affairs Minister Jim Watson has also weighed in on the debate, sending a letter to Ottawa Mayor Larry O'Brien to question whether the city has the money to pay for its share of the project.

Last week, O'Brien told CTV Ottawa he guaranteed the transit deal would be approved on Wednesday. Some councillors, however, predict the vote is going to be close.

"I think we have to show a united front. I lose council decisions all the time, but at the end when that decision is made, I go on side with it . . . I think councillors have to pull together for the good of the city," said Coun. Rainer Bloess.

"If it doesn't go through, I think we basically won't have to start right back from the beginning, but we will have to go back and re-evaluate a lot of the information we were given and take a look at different concepts," said Thompson.

With a report from CTV Ottawa's Catherine Lathem