This Thursday, four of the front-runners in the Auckland Super City mayoral election go head to head in the New Zealand Herald Great Debate.

John Key has ordered an inquiry into how former top defence scientist Stephen Wilce was given top security clearance by the SIS.

The deputy mayors of Auckland City and Manukau councils, David Hay and Gary Troup, say why they think their leader is the best person to be the first mayor of the Super City.