Phil Bond

I have a 2007 S type 2.7 diesel. There is a problem with the ignition system, as at the moment the key will not turn in the lock, and doesn't make the usual recognition sound when you insert key. I don't think the problem is with the key as it still operates the central locking etc. I did have new battery fitted in key, but to no avail. Anyone got any ideas. Thanks.Phil ,