Andrew Geddis: election dates explained

Winston Peters has joined the call for the general election to be delayed until the 21st of November - backing the date put forward by National and ACT. Parliament is set to dissolve today ahead of the election on 19 September, but the Prime Minister will announce whether or not it will go ahead as planned at 10am today. Professor of Public Law at the University of Otago Andrew Geddis told First Up's Louise Ternouth how election dates can be changed.