National's deputy Nicola Willis wants a third supermarket competitor to break up the current duopoly - and says she'll seek advice on how to make that happen once she's finance minister.
The online grocer Supie - which was set up two years ago - has gone out of business with debt of about $3 million.
Willis says she was gutted to hear the news - both for the employees and the wider sector.
National supported the Labour government's move to appoint a grocery commissioner and establish a code-of-conduct.
