Reimplementing 30mph speed limits on Welsh roads could cost up to £5 million, the Welsh government has said.

Ken Skates, the Welsh transport minister, announced on Tuesday that the government in Cardiff Bay will be revising its guidance to councils on which roads can be exempted from the new lower 20mph speed limit.

The move could see councils able to return roads to their previous speed limits by the end of the year.

Mr Skates has admitted that the cost of revising roads back to their previous speeds could be up to £5 million.

This comes in addition to the roughly £34 million it cost to roll out making the default speed limit in built-up areas 20mph in September last year.

Mr Skates made the admission in an interview with LBC.

A Welsh government spokeswoman confirmed the figure is expected to be between £3-5 million, but stressed it was heavily caveated and depended on the number of roads that need to be changed back.

Mr Skates has promised to work jointly with local authorities to prepare the ground for changes, revising the guidance on which local roads can be exempted from the lower speed.

The revised guidance will be published in July, with councils expected to start detailed consultation on changes from September.