The Federal Government has refused to rule out allowing first home buyers to access their superannuation before retirement to pay for a deposit.

The proposal was floated by former treasurer Joe Hockey in 2015 but was strongly condemned by the now Prime Minister Malcolm Turnbull as "a thoroughly bad idea".

Finance Minister Mathias Cormann was also strongly opposed to the proposal and said it would do nothing to address housing affordability and only increase property prices.

But on Tuesday, Assistant Treasurer Michael Sukkar would not rule out the changes ahead of the May budget, saying instead any changes needed to be "finely calibrated".

Mr Sukkar would not comment on any housing affordability measures in the budget and said Mr Cormann's criticism of the proposal was "largely correct".

"Well intentioned though it was, the first home owners grant was ineffective, should have almost been paid straight to property developers," he told Sky News.

Mr Sukkar repeated Treasurer Scott Morrison's comments, saying the key to addressing housing prices in Melbourne and Sydney was to increase housing supply.

"I can assure you, anything that we do on the demand side of the ledger in the housing affordability package will be finely calibrated to make sure we are not just lazily pumping more money into the market," he said.

"We know, consistent with the Minister for Finance's comments, that just pushes up prices.

"We have got to be a bit more sophisticated about it and I'm confident we will be."

An analysis of housing and superannuation data found the average superannuation balance for young people fell below the median 20 per cent deposit for their state's capital city.

The median house deposit for the Greater Sydney area does not fall below the average household superannuation balance until people reach the 45-49 age bracket.

In both Victoria and the Northern Territory, the average household superannuation balance outstrips the median housing deposit for the capital cities slightly earlier at the 40-44 bracket.

'Ramifications run through the community': Morrison

The proposal to unlock superannuation was taken to the 1993 election by both sides of politics, but was scrapped by former prime minister Paul Keating amid widespread criticism.

The Committee for Economic Development of Australia returned to the idea in 2015, calling for superannuation to become an after-tax payment to address equity concerns.

The Grattan Institute's John Daley has previously said the proposal would help first home buyers save for a deposit, but would mean worse affordability for buyers overall.

Mr Morrison has flagged action on affordable housing in the May budget including the provision of cheap loans to low-income earners who are facing rental stress.

He has also welcomed the Victorian Government's decision to abolish stamp duty for first home owners purchasing property valued below $600,000, despite saying it would do little to address supply issues.

On Monday, he said many young people were putting off having children until they could afford to own a home.

"That is a big challenge, particularly for young people, and people are putting off when they buy their house, they're even putting off when they have kids so they can save more," he said.

"The ramifications of this run right through the community in many different ways and that's why it's a very important issue, and that's why we'll be addressing it in the budget."

Mr Morrison said any attempt to address housing affordability needed to consider a "whole range of things" and could not focus on negative gearing alone.