Rail passengers have expressed their anger after being told trains were delayed due to "strong sunlight".
Services at Lewisham, south-east London were disrupted because of the angle of the sun, train operator Southeastern said.
The rail firm posted on Twitter: "We had severe congestion through Lewisham due to dispatching issues as a result of strong sunlight."
It added: "The low winter sun has been hitting the dispatch monitor which prevents the driver from being able to see."
But some travellers were unimpressed by the explanation.
Julie Clarke asked Southeastern: "How do they go on in hot countries where they have sunshine all the time?"
Paul Malyon described it as "the weakest excuse ever" while Brian Barnett wrote: "Leaves on the line. Wrong snow. Now sunshine! Let's think of next excuse?"
A spokesman for Southeastern said: "We know that sometimes it seems that if it is not leaves on the line or snow on the track then it is some other weather issue.
"But actually glare this morning made it impossible for some drivers to see the full length of their train in their mirrors before leaving stations.
"When this happens they have to get out and check to ensure everybody has got on or off the train safely before they can move. This can take a little more time but thankfully for all it doesn't happen very often."
Meanwhile, all services between Lewisham and Dartford via Bexleyheath were cancelled for the rest of the day following a landslip at Barnehurst.
A limited replacement bus service was in operation although passengers were advised to use alternative routes.
There were also problems on the Southern network as a sinkhole caused trains between Redhill in Surrey and Tonbridge in Kent to be suspended.