The voters of the Auckland seat of Maungakiekie elected Vernon as their electorate Member of Parliament in the 1996 election, but she lost the seat to Labour's Mark Gosche in the 1999 election, returning to Parliament as a list MP. In the 2002 election she failed to re-take Maungakiekie, and owing to the collapse of National's vote that year, was not high enough on the party list to return to Parliament.
