The New South Wales government has more than doubled the number of drivers to get cut-price car registration before the March state election.

Premier Gladys Berejiklian on Monday announced about 160,000 drivers who spend at least $15 a week – or $780 this financial year – on tolls will get half-price vehicle registration.

That’s on top of the 140,000 drivers already eligible for free rego for spending more than $25 a week, or $1300 a year.

Eligibility will also change to allow families to pool their toll use together and get the discount if their vehicles are registered to the same etoll account.

The policy is expected to cost $104 million in its first year.

NRMA spokesperson Peter Khoury said the motoring body supported Monday’s announcement.

“We support anything that’s going to reduce the cost of motoring on our members and on our community,” Mr Khoury told The New Daily.

He said the original policy also had NRMA’s support.

“By the same token, we think that this will help just provide some relief to families who are exposed more so than others to tolls.”

Ms Berejiklian said private cars, utes, four-wheel-drives and motorcycles would be eligible to help ease the cost-of-living burden.

“As a government we need to do everything we can to reduce the cost of living pressures on families and we have,” she told reporters on Monday.

So far, 46,000 drivers eligible for free registration have saved a total of $20 million since that discount came into effect on July 1.

The suburbs saving most were Castle Hill, Baulkham Hills, Kellyville, Blacktown, Mosman, Quakers Hill, West Pennant Hills, Glenwood, Cherrybrook and Glenmore Park.

Opposition Leader Michael Daley on Monday said while it was bad policy, he would continue the rego rebate for drivers spending more than $1300 in tolls, but would not adopt the government’s expanded policy.

Treasurer Dominic Perrottet responded in a statement on Monday afternoon.

“Michael Daley has been exposed as nothing more than the worst kind of craven political opportunist,” Mr Perrottet said.

Labor has also promised to reintroduce a “cashback” system for the M4 motorway to save western Sydney drivers almost $200 million.

Earlier, Mr Perrottet said that plan would only benefit some toll users.

“Labor’s cynical program will only benefit drivers on one road and cost taxpayers more than $2.2 billion over 10 years,” Mr Perrottet said.

“Our program offers relief to drivers across all toll roads, no matter where they live.”

Transurban, which owns the bulk of Sydney toll roads, made $944 million from Sydney toll users in the past financial year.

Sydney toll revenue grew by 8.3 per cent in the year.

-with AAP