Queues of trucks stretching for five miles unexpectedly built up in Kent on Tuesday after the French started a trial of post-Brexit checks. Lorries on their way across the English channel were forced to stop in long lines up to junction 11 on the M20 as they tried to approach the Eurotunnel entrance just outside Folkestone and the Port of Dover. The queues give a glimpse of things to come in January whether a deal is reached or not with the government last month warning of queues of 7,000 lorries on the main motorway routes to both Eurotunnel and Dover ferries in the worst-case scenario. The delays were caused after the Police Aux Frontières, the equivalent to Border Force, rehearsed new immigration procedures. Under the Le Touquet agreement, French authorities conduct immigration checks at the UK side of the tunnel and the port. A spokesman for Highways England said they had been told a new trial software for border checks, with all HGVs been checked from 6am until 3pm, was responsible for the delay. “On a conference call chaired by Kent Police at 16.00 we were informed that the trial has now finished and traffic is now free flowing within the port. The queue of HGVs is backed up to around M20 J11, but we expect this to start to ease given the trial is no longer operational,” said the spokesman. Eurotunnel and Port of Dover was also on the call. The controls require truck drivers to provide passports, and are asked about proof of means, their destination and length of stay which can last up to 70 seconds per passenger. After January truck drivers, will also face additional delays for checks on food, drink and agricultural products and customs in both directions. However, the UK government has said it will phase these checks on the British side over six weeks to reduce the chances of gridlock in Dover and on Kent roads One source said the dry run caused delays because the French had not deployed enough staff needed for a live operation and once properly resourced more lanes would be open to help ease the congestion. The delays will also concern the UK haulage and customs sector which has warned the government repeatedly about the delays in key British software which will not be available until December. Last week Kent county council also expressed worries over the welfare of animals that could be stuck in lorries in the event of a standstill. “We do have concerns over the impact the road system will have, and particularly the impact on animals in transit,” said Steve Rock, head of trading standards. The council is looking to double the number of trading standards officers from six to 12 to cope with Brexit checks and are concerned that routine deliveries of veterinary medicine to farms and getting animals off farms to markets are not disrupted by Brexit. Tuesday’s Brexit tests come a day after the UK government confirmed it would be shipping portaloos to the motorways as a “reactive” plan when long queues occur. It decided against installing them on a longer term basis because of risk of drivers needing a convenience break stopping to use them when traffic is flowing at normal levels. The Department for Transport is looking to hire private contractors to assist Kent Police in managing the traffic although the local police have said if any extra workers are brought in they would not be involved in any enforcement action.