The new toll bridge is known for now as a "new bridge for the St. Lawrence," Lebel said as a news conference in Montreal on Thursday.
A temporary causeway, which will run along the current Nuns' Island Bridge, will have three lanes in each direction.
The federal government is primed to request proposed plans and designs for the temporary span, Lebel said.
A 2011 report on the Champlain Bridge's condition estimated that major repairs to prolong its life would cost an estimated $25 million over the next decade.
The report concluded the bridge would have to be replaced eventually, even with repairs.
The Champlain Bridge was officially opened as a toll bridge in 1962.
The tolls were eventually abolished in 1990.
It is Canada's busiest bridge, with an estimated 160,000 vehicle crossings every day.