Emergency crews were called to the scene of the accident, on the A1123 between the Compass Point and Needingworth roundabouts, at 8.20am. Fire-fighters have put a cordon in place around the vehicle and the road remains closed. A fire service spokesman said they were called at 9am and crews from St Ives and Huntingdon attended, as well as a fire engine and the Hazardous Material Unit from St Neots. The tanker was carrying approximately 9,000 litres of liquid fertiliser. Fire-fighters have been working to stop a leak from the tanker and prevent the fertiliser entering the water course. Crews are also working with a recovery team to get the tanker back onto its wheels.