Helen Clark has slammed the National Party on Twitter, challenging the party's claim that Labour will shut down big infrastructure projects.
The National party posted a photo of the Waterview Tunnel on Twitter, with the caption: "Labour want to stop the projects & live on the vision."
The page also included the hashtag, #LetsNot.
However Helen Clark, who led the Labour Party as Prime Minister from 1999 to 2008, was quick to point out the Waterview Tunnel wasn't actually National's idea.
"The decision to build the Waterview tunnel rather than wreck the suburb with a motorway was made by my Government," she replied.
National Party MP Steven Joyce was quick to reply, saying it was the National Party who actually made it a reality.
"[The] govt that called it in [with] new RMA rules, built it, and made it a land wider in each direction & spent [$1 billion] less on it than planned is this one."
The exchange has sparked a long chain or replies, most of them in Helen Clark's favour.