The portion of income going towards rent has reached its highest level since 2014, according to new analysis by ANZ and property data firm CoreLogic.

The report found the median income household would need to part with 30.8 per cent of their income to service a new lease.

The picture is much bleaker for lower-income households, with those in the 25th percentile income level dishing out 51.6 per cent of their income.

This puts this cohort firmly in housing stress as commonly defined by the "30/40" rule, which is where the lowest 40 per cent of income earners are spending more than 30 per cent on housing.

The report noted that there has always been a big difference in housing affordability for median and low-income renters but this gap was getting wider, suggesting poorer households have been hit much harder by rising rents.

CoreLogic Australia head of research Eliza Owen said there had been some "extraordinary shifts" driving up demand for rentals, including that there were now fewer people per home and overseas migration had returned with a bang.

On the other side of the ledger, investor conditions had not been ideal and stemmed the flow of new rental supply.

"As rents have risen sharply, the increase in the cash rate, and pressures in the construction sector have slowed the rate of dwelling completions," she explained.

However, Ms Owen said an uptick in investor borrowing suggested more rentals are coming but would take some time to materialise.

At 1.1 per cent nationally, rental vacancy rates are well below the three per cent decade average.

New listings also remain well below average.

ANZ senior economist Felicity Emmett said the period of economic uncertainty was also weighing on sales in the private market and leaving more people in the rental market.

"Paired with a decline in social housing, rental demand pressures are being felt in all income brackets," Ms Emmett said.

The federal government has been under pressure to ease pain points in the rental market but the centrepiece of its plan, a $10 billion housing future fund, has struggled to make it through parliament.

The Greens have been blocking the fund, which would generate returns to spend on building 30,000 social and affordable homes over five years, in the hopes of squeezing more ambition out of the government.

Liberal MP Jason Falinski said planning regulation and community opposition were holding up the supply of new private dwellings.

In Sydney, he said the city council had prevented more apartments from being built in inner city areas.

"The biggest cause of housing affordability in Australia is not tax, is not immigrants, is not foreign investors," he told Sky News on Monday.

"It's (City of Sydney Lord Mayor) Clover Moore who refuses to allow more dwellings and more apartments to be built in areas where people want to live."

Assistant Minister to the Prime Minister, Patrick Gorman, said the federal government wanted to solve some of the land supply and planning control issues raised by the Liberal MP through the National Housing Affordability Supply Council.

"I advocate for good quality medium density," he told Sky News.

"I want more social housing for my electorate, that's why I'm voting for the Housing Australia Future Fund."

Australian Associated Press