The federal Minister of Infrastructure, Denis Lebel, has announced a $70 million investment to build a temporary causeway linking Nun's Island to Montreal — at the same time promising to make all urgently needed repairs to the Champlain Bridge.

Lebel was in Montreal Wednesday to announce construction of the causeway.

He also said a new inspection report shows some repairs can't wait until the new bridge planned for 2021 is completed.

"Some of these repairs will be done in the coming days, while others will take a few years," said Lebel.

Champlain Bridge repairs

Work continues on the ageing Champlain Bridge. (CBC)

The president of Jacques Cartier and Champlain Bridges Inc., Glen Carlin, said the immediate concern is making sure the bridge's exterior beams are safe.

"We're going to be installing kind of like a fibreglass tissue that is applied on the exterior of the beams," Carlin said, "and this is going to reinforce these beams just to give us that additional level of confidence of security."

Carlin said the bridge is safe and meets all federal regulations.

The first phase to replace the bridge is meant to ease traffic when construction begins on the Champlain Bridge's replacement.

"It will have seven lanes – three in each direction – and unlike the current bridge, it will have a lane reserved for buses," Lebel said. "It will also have pathways for pedestrian and cyclists."

The causeway is scheduled to be ready in two years .