The State Opposition says the Government's decision to abolish free parking at train stations will cost the average commuter more than $400 a year.

From July 2014, commuters will be charged around $2 per day to park at metropolitan stations.

Charges already apply to about one quarter of the 20,000 parking bays across Perth, with the changes expected to net the government an extra $50 million over four years.

The Opposition Leader Mark McGowan says it is blow to all public transport users.

"This is a $460 impost on your average commuter that they were not told about before the state election," he said.

"This will reduce the incentive to catch the train, it will increase the pressure on surrounding streets with parking and commuters have every right to be unhappy."

Mr Buswell has rejected the suggestion that paid parking will discourage people from using public transport.

"I reckon that on the first of July, if it's a week day and the $2 applies, the car parks will be as full as they are today," he said.

The government will also increase public transport fares by 20 per cent over the next four years.