Swan on the line (Photograph: @martin466004)

In a statement on Twitter just after midday, Southern Rail said: “️Due to a very stubborn swan on the line between Hove and Worthing, all lines are currently blocked.

At 12.45pm, Southern said: “Earlier today a swan took up residence on the track. Network Rail response staff have been able to convince the swan to board one of the trains in the area and the line has now reopened, however as services have been at a stand for approximately 40 minutes train carriages and crew will not be in the correct places to start their next journeys and it may take some time for trains to return to normal.”