Southern Rail's 7.29 Brighton to London Victoria train is Britain's worst train service.
Figures reveal that the train failed to arrive on time on any occasion out of 240 attempts in 2014.
The service is on of Britain's busiest commuter trains, reports the Telegraph. It is scheduled to arrive in London at 8.35am in time for a 9am start at work.
Southern Rail's managing director David Scorey admitted that they are not delivering the level of performance customers expect, the Evening Standard reports.
"We are delivering in a lot of areas, including investment and innovation, but not on performance. We're doing more in that area, that's a major area we're focusing on", he said.
"Our network is very busy and congested. An analogy that I'd use is the M25 at its busiest time.
"Our network is a bit like that and what we're trying to do is run as many trains as we can because the capacity is needed.
"People want those trains, want seats on the trains, want trains to be as long as they can because there is demand for it.
"But it does mean that trains are running very, very close together - particularly as they approach London.
"We've identified some issues with the 7.29, with the way it interacts with other services, but the timetable and the capacity demand is so intense that some of the options of what we can do are quite limited."
Rail commuters warned of more delays
Train fare rises 2015: How new rail price increases will affect you