Southern and Thameslink were unable to run trains between Three Bridges and Haywards Heath this morning until 7.20am because of problems Network Rail experienced during overnight engineering work.
Network Rail’s chief operating officer for the South East, Andy Derbyshire, said: “I'm really sorry for the unnecessary disruption to the passengers on the Brighton mainline this morning.
“As part of our ongoing track and signalling improvement work, we were undertaking track work in the Balcombe tunnel area last night. One of our heavy engineering machines suffered a break down late into the works, causing the delay to opening the line this morning.
“I will be investigating the cause of breakdown but sincerely apologise for this delay to your journey.”