A decision about whether people should be automatically enrolled in KiwiSaver could be made before the election, Prime Minister John Key said today.
Under the current scheme, people are automatically enrolled when they start a new job and are given the choice to opt out.
Mr Key said the Government was considering an option in which those who have not moved jobs since the scheme started would also be automatically enrolled.
"We are asking IRD and Treasury to provide us some advice on how auto enrolment might work and we think it's very interesting," he said.
"It will be something we either campaign on, or simply decide that we do want to do."
Finance Minister Bill English said cost was a big part of what officials were looking at, and that it was unlikely the $1000 government contributions alone would cost $1 billion as had been reported.
"If people aren't in KiwiSaver now when it is a very good deal, then they might have quite good reasons for it," he said.
"A big mortgage, just had another baby, one of them's had to stop work - there's any number of reasons so we shouldn't assume that the million Kiwis who aren't in it want to be in it."
Labour leader Phil Goff has not said what his position on introducing a compulsory savings is, and that his party was looking at all options for its savings policy.
"We're mindful of the fact that New Zealanders can't afford to spend much more than they are at the moment because of the pressure of rising prices," he said.
"Labour will have a savings policy that will lift savings that's affordable and workable, but we're looking at all options."