David Seymour has today launched his Epsom electorate campaign in a bid to secure the seat in central Auckland.

The ACT leader remains confident of retaining the seat, despite pressure from the unitary plan to expand housing in the area.

Mr Seymour earlier said the plans should spark alarm bells due to schools and public transport being at breaking point.

He also said there needs to be more investment in infrastructure in the future.

However, Mr Seymour told Newstalk ZB that the number one priority in the Epsom electorate "is defending the school zones for people who have bought into an area to send their kids to a certain school."