PLANS to remove the hard shoulder on the M4 should be halted until they are proven to be safe, according to MPs.

The bid to convert the surface into a fourth lane and create a so-called "smart motorway" from Theale into London has already received objections from Reading Borough Council and environmental groups.

Members of the Transport Select Committee have today (Thursday) published their findings which are calling on the government to pause its plans to roll out similar schemes throughout the country.

In it they claim the potential risks of losing hard shoulders permanently would be an "unacceptable price to pay" for any improvements in journey times.

The report added that one year of data from expansions on the M25 were not enough evidence to use in deciding to roll out 'all lane running' on a national level.

Louise Ellman MP, chair of the Transport Select Committee, said: "The permanent removal of the hard shoulder is a dramatic change "All kinds of drivers, including the emergency services, are genuinely concerned about the risk this presents.

"It is undeniable that we need to find ways of dealing with traffic growth on the strategic network.

"But all lane running does not appear to us to be the safe, incremental change the Department wants us to think it is."

Plans to convert the hard shoulder between junctions 12 and 3 of the M4 into "running lanes" were launched last year as part of nationwide scheme to open up 300 miles of motorway.

Following a series of public meetings throughout Berkshire the designs are currently sat with the Planning Inspectorate.

They will return a verdict on whether the scheme - costing up to £860m - should be allowed to go ahead.

Cllr Tony Page, Reading's lead member for transport, described the report as "pretty devastating" and said he hoped the Department for Transport would take it on board and put the scheme on pause.

He added: "The language used and the very substantial criticisms of the DfT are I think quite persuasive and it encompasses some of the concerns that Reading Borough Council has put forward of the last few months."

A DfT spokesperson said: "Our motorways are among the safest in the world, and cutting the number of accidents is our top priority. all lane running roads are designed to be as safe as ordinary motorways.

"In the two all lane running sections on the M25, accidents were down 17 per cent and casualty rates fell by 21 per cent in the first year.

"As the committee recognise, the busiest journey times have almost halved, and overall journey times are more reliable and predictable than before. We will be considering all the Transport Select Committee’s findings carefully and responding shortly."