The NSW opposition leader has called for a cap on Australia's migrant intake as Sydney and Melbourne reach infrastructure breaking point.

Sydney’s pull as the largest city and a job magnet has contributed to one-third of the nation’s migrants coming into the city, Luke Foley says.

“The challenge we face at the moment is the capacity of our largest cities – Sydney and Melbourne – to absorb the very large numbers of migrants that are coming in,” Mr Foley told 2GB radio on Monday.

“Sydney full of towers is the inevitable consequence of the current very large migrant intake.”

One year out from a state election Mr Foley has called for a set number to be placed on Australia’s migrant intake – to be made in consultation with all states and territories and the federal government.

Mr Foley’s comments come as Australia’s population is expected to tick over 25 million this year – a number the nation wasn’t meant to reach for decades.

Social researcher Dr Rebecca Huntley told ABC TV’s Four Corners program the population increase won’t be a result of larger families but from immigration.

As the population grows, experts are becoming more concerned about how major cities such as Sydney and Melbourne will keep up with the pressure on infrastructure, health and education.

“We’ve done an abysmal job,” Australian Industry Group chief executive Innes Willox told Four Corners.

“There has been really no serious integrated debate around all the key factors that population growth brings to our economy and our national way of life.”

Infrastructure Australia chief executive Philip Davies has called for Australia to up its game in terms of planning as Sydney and Melbourne start to mirror global cities like London and Hong Kong.

Australian businessman Dick Smith, who last year launched a $1 million TV campaign calling for a limit to the number of immigrants, sees disaster for the Australian way of life.

“You’re jammed like a termite in a high rise, or I say battery chooks,” he told Four Corners.

“To buy a house with a backyard to play cricket and have a cubby house, that’s gone forever.”