National would automatically enrol babies and make KiwiSaver compulsory for all workers.

Campaign chair Simeon Brown earlier compared National's coalition partners to children.

The National Party plans to make KiwiSaver compulsory for all workers, if re-elected, as part of a suite of changes that would cost more than $1 billion over four years.

National would automatically enrol babies and make KiwiSaver compulsory for all workers.

The Prime Minister believes it would be difficult for other parties to argue against the KiwiSaver changes National is proposing, and is keen to see some cross-party buy-in.