Commuters travelling to London are facing major disruption on Monday with services impacted by a landslip and a “substantial” signalling fault.

National Rail has warned passengers on Great Western Railway and the Elizabeth line face delays and cancellations until the end of the day because of a landslip between London Paddington and Reading.

Two out of four lines in the area have been blocked off after an “unstable area of surrounding earth” was identified between Twyford and Reading.

The landslip has affected various Great Western Railway routes connecting London to the South West and Wales as well as the the Elizabeth line between Abbey Wood to London Paddington and Reading.

The National Rail website reads: “An issue has arisen with the state of some trees at the side of a cutting between Twyford and Reading where an unstable area of surrounding earth has been observed.

“Owing to its location, it is not an issue that can be easily resolved. 

“Until the matter has been addressed, two of the four running lines in the area will be taken out of use and the remaining line capacity will not be able to carry the full advertised train service.”

Separately, travellers on Southern and Thameslink services have been warned to expect major disruption on services between Brighton and London until midday because of a “substantial” signalling fault.

The disruption is affecting several routes including the Gatwick Express, which runs between London Victoria and Brighton, and Southern services between London Victoria and East Sussex.

Thameslink trains between Cambridge and Bedford to Brighton have also been affected.

A statement on the National Rail website reads: “A substantial fault has occurred overnight, affecting signalling equipment between Three Bridges and the South Coast.

“Southern, Thameslink and Gatwick Express are working to run as many trains as they can, but despite much of the equipment being restored, there are still problems with various sets of points.”

Passengers have been warned it is likely usual journeys will take up to an hour longer with travellers likely to need an alternative route or to change trains more often.