Road chaos could continue into next week, with only northbound traffic flowing between junctions 1 and 4 for now All southbound lanes of the M1 between junctions 1 and 4 will remain closed until further notice because of fire damage, the Highways Agency has warned. The seven-mile section has been shut since Friday after a blaze at a scrap yard underneath an elevated section of the motorway in the Mill Hill area of north London. The roads minister has said the full width of the motorway will not reopen until the middle or end of next week. The Highways Agency had hoped to reopen a southbound lane by Monday morning, but is now warning the closure could continue into the week. Two lanes on the northbound carriageway were reopened on Sunday but motorists were advised to avoid the route due to congestion. The agency said: “We are working in very difficult conditions in a confined space and have encountered unexpected difficulties in manoeuvring some of the large and heavy equipment required to reinforce the bridge deck.” It would reopen the fire-damaged southbound stretch as soon as it was safe to do so, it added. The roads minister, Mike Penning, told Sky News the full width of the motorway would not open until the middle to the end of next week. He also told BBC Breakfast: “We will do everything we can to get the southbound stretch open today, but sadly the inside lane on the hard shoulder was so badly damaged it is beyond repair and we’ll have to do remedial work on that later on. “We’re looking to open two lanes south today and operate a contraflow using the hard shoulder on the northbound carriageway to have three lanes north and three lanes south. We are working as quickly as possible to reopen lanes on the M1. However safety has to be paramount.” The closures, between Brent Cross and Elstree, disrupted the plans of thousands of people, including football fans travelling from Manchester, Bolton and Stoke for two FA Cup semi-finals at Wembley over the weekend and others visiting for the London marathon. Penning appealed for motorists to seek alternative routes along the M40, A41 and A1. He said he was sure government agencies would look at how many scrap yards and stores were built under roads after the effects of the Friday fire. An AA spokesman said the minister’s remarks were “a bit worrying”. He said there were also hundreds of railway viaducts where inflammable materials were stored under arches. The transport department said it would be looking at the scope of any future motorway checks over the next few days. The reinforcement of the elevated section has involved putting new supports under the road. One lane northbound was opened on Saturday evening but drivers will continue to face delays and diversions for some time. Penning said: “We have to build a new bridge underneath the existing bridge so we can open more lanes and get traffic moving safely.” In the interview with Sky News he said the hard shoulder was particularly badly damaged. “It is a precast concrete bridge and the heat has damaged it so badly that the steels are exposed that are part of the infrastructure of the bridge.We have to make sure it’s safe for the motorist and safe for our workers underneath the bridge. “I am sure there are hundreds and hundreds of these sorts of scrap yards and storage places. We don’t know exactly what was stored here – the local authority will be involved on Monday morning – but the key is to make sure we get as much of the motorway open as soon as possible, but safely. As a former firefighter I know firsthand the intensity of fires of this kind. I’ve seen the damage to the bridge and it should not be underestimated.” Scores of firefighters tackled the original blaze, which led to the evacuation of nearby homes and disrupted rail services. A hazard zone was set up because of gas cylinders at risk of exploding. The Manchester United manager, Sir Alex Ferguson, described the decision to play two semi-finals involving four northern clubs at Wembley as “quite incredible”. Supporters of a high-speed rail link to the north are also likely to point to the weekend road chaos as evidence for their cause. Transport James Meikle guardian.co.uk