Infrastructure Minister Chris Bishop warned the Government may need to put a toll on the Auckland Harbour Bridge to fund the new Waitematā crossing.

The new crossing will be tolled, but the Government is getting advice on whether the existing bridge needs to be tolled as well - in order to stop people from using the old bridge to bypass the toll.

Newstalk ZB senior political correspondent Barry Soper explains why this idea isn't realistic for commuters.

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