The strategic vulnerability of the M4 in south Wales has been highlighted after a lorry fire on Tuesday closed the motorway for most of the day.

Six appliances were called to the incident shortly after 8.30 am where crews were faced with a well developed fire and large volumes of black smoke.

Only one lorry was involved in the fire and there were no reported injuries, but the damage to the tunnel has been extensive. Structural engineers are currently assessing the damage.

The eastbound section of the tunnel was reopened later in the day and a contraflow system was provided to get traffic moving in both directions, and this is expected to continue for the next few days at least.

A Welsh Government spokesperson said yesterday:

“Our team has worked throughout the night to clear the debris and make the site safe for our engineers to carry out a full structural, technical and safety assessment of the tunnel. Once these assessments are completed we will know the extent of the damage and the work required to bring the tunnel back into use.

But David Rosser, director of CBI Wales, told BBC Radio Wales on Wednesday he was very concerned about the situation.

"There will be people yesterday who missed flights, people who missed business meetings, deliveries on a just in time basis which weren't there just in time, and obviously people commuting to work who didn't get to work at any sensible time yesterday."

Referring to plans which were shelved in 2009 to build a relief road south of Newport, he added: "The key issue for me, though, is that the Welsh Government's been warned about this problem for some years now.”

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