A MAJOR landslip in Warwickshire is threatening to block the Chiltern main line between Banbury and Leamington Spa.

An estimated 350,000 tons of soil and rock slipped from the side of a cutting near Harbury Tunnel around 15.00 on Saturday afternoon, and the slipped material is posing a major danger to trains. The line has been closed as a precaution.

Chiltern, CrossCountry and freight services are all affected by the incident, and the line is expected to remain closed for at least a week.

Replacement buses are running between Leamington and Banbury, and Network Rail has also suggested that commuters could drive south to Banbury. Passengers travelling towards Birmingham are being advised to use Warwick Parkway. Revised train timetables have been introduced on either side of the blockage and tickets are valid on all other reasonable routes, including Virgin and London Midland services from Coventry to London.

The area is known to have ground water problems. Network Rail said the landslip is 'extremely significant', and that the tunnel itself has also been affected. Engineers are also liaising with local landowners.

The engineers are assessing the situation to see how stable the area is before any clearance work can start.

In a statement, Chiltern Railways provided some background to the situation: "Our railway runs through a deep cutting between Banbury and Leamington Spa. This embankment has been a particular problem since it was first built by Brunel in the 19th century, as it was originally intended to be a tunnel. This results in an unusually steep embankment, with a lot of earth and stone above the railway line.

"This embankment is under a regime of careful monitoring. There was a landslip on this embankment on Febuary 14 last year in which some earth and stone fell on to the railway. This was resolved at the time and further monitoring put in place and work undertaken to seek to resolve things for the longer term, with a speed restriction past the site.

"However, a major fault line has now opened up in the embankment. This fault is around 150 metres long. While no earth has fallen on to the tracks, there is now a very serious risk of earth and rock falling on to to the railway as there is movement in the earthwork above. We estimate that there is around 350,000 tonnes of earth and stone that needs to be excavated to remove the risk of these moving towards the tracks or being dislodged by the vibrations of a passing train. We anticipate this may require around 20,000 lorry loads of earth being removed from the site.

"We obviously never make compromises with regard to safety, therefore the railway must be closed until we can be certain that the embankment is safe."