DISABLED motorists will be forced to pay between $40 and $60 for their "free" e-tag from next month when the Harbour Bridge goes cashless. And drivers who do not use their e-tag regularly will have to pay a fee, the NSW Opposition has warned.

The Roads and Traffic Authority issues free passes for disabled motorists to use on the bridge. But the Opposition roads spokesman, Duncan Gay, said these drivers would have to pay a deposit for an e-tag when the remaining cash booths were removed from the bridge.

Yesterday the Opposition called for NSW to follow Queensland and Victoria and provide e-tags without deposit for all motorists after figures showed that e-tag providers had taken almost $60 million in upfront deposits for tags.

The figures revealed that the RTA was holding more than $30 million in security deposits for e-tags, and Sydney's other tag providers, Roam and E-Way, had almost $50 million in deposits and minimum account balances.

The RTA says the deposit helped the authority cover the cost of buying the tags and replacing faulty ones, but Mr Gay said the Government should be focused on easing congestion, not charging motorists unnecessary fees.

"At a time when the Government is trying to get us to move to electronic tolling, they should be encouraging motorists in every way possible. Yet once again we see NSW lagging behind Queensland and Victoria, both of whom provide e-tags without a deposit."

Disabled motorists, including returned service personnel with a disability, had been unfairly targeted, he said. "Those who currently qualify will now be forced to pay for their 'free' entitlement. Infrequent users will need to pay $40, while frequent users will have to pay $60 to receive a special e-tag entitling them to so-called free travel across the Harbour Bridge or through the Harbour Tunnel."

Motorists were also being fined a $6 "inactive use fee" if their e-tag was not used for six months, he said.

Last month it emerged that some motorists were being charged twice each day for the e-tag toll to cross the bridge, because of a faulty scanner.

This might have added as much as $4 million to the RTA's coffers.