NO trains are running in and out of London Paddington this evening.

Network Rail engineers are on the site at Stockley, between Paddington and Slough, working on signalling problems.

UPDATE: Great Western Railway has now said every line between the capital and Slough IS blocked.

The issue caused chaos for Heathrow passengers as no trains were able to operate to or from the airport as the Heathrow Express and Heathrow Connect were suspended.

London Paddington had suffered disruption due to a signalling failure on Wednesday evening.

Network Rail - which manages Britain's railway infrastructure - and GWR said in a joint statement: "Network Rail and GWR would like to apologise to customers as a signal failure means we are not currently able to run trains into and out of London Paddington.

"Network Rail has teams on the ground working to resolve the issue as quickly as possible, however significant delays are expected to continue."

Affected passengers were advised that they may be entitled to a refund or compensation and should visit gwr.com for more information.

GWR advises those wanting to travel to visit www.gwr.com/travel-updates/live-network-updates