Rail services between Brighton and London have been left in chaos this morning after a number of signal problems caused delays and cancellations.
One service from London Bridge suffered delays after someone trespassed on the line.
Another service was disrupted due to lack of available train crew.
The signal issues are continuing to disrupt Brighton to London services with the 11.49 Brighton to London service being cancelled as well as the 12.06, 12.36, 13.06 London to Brighton services.
In a message on Twitter Southern Rail has advised passengers to expect delays of up to 40 minutes with short notice cancellations still possible.