The construction of new all-lane running motorways should be paused until safety concerns are addressed, MPs and campaigners have said.

A new Transport Select Committee report concluded there was not enough safety and economic data to justify continuing with the Government’s plans to roll out an additional 300 miles of all-lane running motorway by 2025.

The report said Government plans to remove the hard shoulder from all future smart motorways and use the lane for live traffic are "premature".

It added: “The Government and National Highways should pause the rollout of new all-lane running schemes until five years of safety and economic data is available for every all-lane running scheme introduced before 2020 and the implementation of the safety improvements in the Government’s action plan has been independently evaluated.”

Demonstrators carried 38 cardboard coffins to the Houses of Parliament on Monday – representing those killed on smart motorways since 2014 - in protest over the Government's motorway plan, which was first announced in March last year.

The Department for Transport said it would consider the recommendations.

'Smart' or 'all-lane running' (ALR) motorways have been under the microscope since 2019, when it was revealed that National Highways (formerly Highways England) had not fully investigated the dangers of removing the hard shoulder.

In September, The Office of Road and Rail (ORR) published a report that backed up claims by National Highways that smart motorways are the safest roads in the country in terms of fatalities.