Motorists who spend $25 a week or more on road tolls in Sydney will be granted free car registration, the NSW Government has announced.

The decision comes after the reintroduction in August of tolls on a widened section of Sydney's M4, between Homebush and Parramatta, sparking suggestions there should be a nation-wide cap on tolls to ease financial pressures.

Sydneysiders are currently being tolled for the M1, M2, M4, M5, Eastern Distributor, Harbour Bridge, Cross City, Lane Cove and Harbour tunnels. Some of these tolls exceed $7, while annual vehicle registration costs between $350 and $700.

But not everyone welcomes Premier Gladys Berejiklian’s plan. “The Government is now going to prop up private profits using the lure of free rego for motorists, but only after you’ve spent thousands of dollars in tolls,” said Dr Mehreen Faruqi, Greens MP and transport spokesperson, in an official statement. “This is effectively hundreds of millions of dollars of taxpayers’ money in foregone revenue.”

High tolls have been needed to pay back the $16.7 billion proposal for the WestConnex motorway project; the F6 extension in the south; and the Beaches Link tunnel in Sydney’s north-east.

“Premier Berejiklian keeps building new toll roads, re-tolling the M4 and extending tolls on other roads by decades. That’s the real root of why people are struggling,” said Faruqi. “Sydney is rapidly becoming the toll road capital of the world.”

“People have to use toll roads, not by choice, but because of where they live or what job they might have,” Premier Berejiklian said in an official statement. “This could bring people to roads they haven’t previously used.”

Berejiklian said the free registration initiative would cost the state an estimated $100 million in the first year. “It could be more than that amount into the future. This is a growing cost to government but we know we can afford it,” she said.

Premier Berejiklian rejected suggestions free registration could dissuade people from using public transport, arguing the state would not be spending $20 billion on a new metro train line if “we didn’t believe in public transport”.

“If this government is serious about addressing the cost of living, they should be capping tolls and making sure people have real and affordable alternatives instead of finding a sneaky way to help fill the deep pockets of private companies,” said Faruqi.

The first motorists (cars, utes, four-wheel drives and motorbikes) will be eligible for free registration from July 1 next year. It will exclude trucks and other vehicles weighing more than 2795 kilograms.