RAIL passengers are being warned that services will be disrupted by heavy rain during the evening commute.

Network Rail Wessex (NRW) says a 40mph speed limit will be imposed on some routes amid fears that torrential downpours could result in landslides blocking lines.

Posting on social media, NRW warned that trains operated by South Western Railway and two other companies would be affected.

It tweeted: "Sorry to say we have some bad news.

"A band of heavy rain is about to hit our railway and will impact on SW, GWR and CrossCountry UK tonight, with 40mph restrictions in some places.

"Every one of our most vulnerable earthworks is already saturated with water and for that reason, we are going to have put restrictions in place progressively from west to east as the day goes on, to protect trains from potential landslips.

"Not every line has vulnerable sites, however the impact of the speed restrictions will mean late-running will be widespread and affect trains even on lines without problems.

"We'll be starting at 1600 in the west, 1900 from Basingstoke and 2000 on the main line near Clapham.

"As a guide, sections with 40mph running include the West of England line west of Salisbury, in the Basingstoke area, much of the Portsmouth via Petersfield line, and between Egham and Reading.

"We will be able to carry everyone home tonight, but we would advise customers to allow extra time for their journeys where-ever they are on the network.

"It's difficult to estimate the cumulative impact of the speed restrictions, but it will bring disruption.

"We have not taken this step lightly but the increased risk of washouts from saturated land is too high for us to run trains at full speed.

"Safety is our priority. Thank you so much for your patience and please take care on your way to and from the railway today."