TRAINS from London to Essex are running slower than usual due to overhead wire problems.

Services in and out of London Liverpool Street are running to a revised timetable after cables between Stratford and Chelmsford sagged in the heat.

Network Rail says it is currently upgrading the overhead wire on the Greater Anglia line as part of a multi-million pound project - but this section has not been replaced yet.

Some services are not calling at Romford and journeys are taking longer than usual. The problems are set to continue into this evening's rush hour.

A Network Rail spokesperson said: “We are currently in the middle of a £200m+ project to completely replace all the overhead lines on the Great Eastern Main Line between London and Chelmsford.

“While the core section from Liverpool Street to Stratford has been completed, the sections of railway which have speed restrictions in place today have overhead lines dating from the 1950s and 1960s.

"The wire in these sections can expand and sag in high temperatures and, as a result, it is necessary to reduce speeds in order to avoid damaging the equipment and trains.

 “The contingency arrangements put in place today are tried and tested and are designed to minimise both the risk of damage to equipment and trains as well as any disruption to passengers.”

Commuters are advised to check www.journeycheck.com/greateranglia before they travel.