Network Rail has been fined £800,000 after a track worker suffered life-changing injuries when he was hit by a train travelling at 80mph.

Alan Evans, from Crawley, was struck on the right shoulder and thrown down the side of an embankment on the Brighton main line.

He was leading a maintenance team of 12 people responding to cracks in the track, with lookouts in place to protect the group.

At about the time a warning was given about the oncoming train, the team leader began to walk along the side of the line with his back to the train and was hit.

Mr Evans, who has since left Network Rail, has had 20 surgical operations since the incident on the tracks near Redhill, Surrey, in June 2014.

Network Rail pleaded guilty to two charges under the Health and Safety at Work Act.

According to the Office of Rail and Road (ORR), which brought the prosecution at Guildford Crown Court, the work on the main line between Brighton and London was inadequately planned and managed, placing track workers in unnecessary danger.

Its investigation found that the works were scheduled while fast, frequent trains continued to run, in an area with a narrow, steep embankment.

The court heard the work could have been carried out at night when no trains were running.

ORR principal inspector Tom Wake said: "This incident shows that although Britain's railways are the safest in Europe, we can never be complacent.

"In 2014, Network Rail's planning of track maintenance work near Redhill fell below legal standards, placing workers in unnecessary danger and causing an employee to suffer life-changing injuries."

Network Rail's managing director for the South East, John Halsall, said the organisation's thoughts were with the track worker and his family "as the consequences of this accident continue to affect their lives".

He added: "Safety is our absolute priority and it is clear that we fell short in this instance.

"We have made several changes to the way we work following this incident, including banning working while trains are running on this particular stretch of railway."

The ORR said it would continue to monitor Network Rail and "will not hesitate to step in if needed".