Media playback is unsupported on your device Media caption The derailment near Bletchley has caused delays all day

A freight train engine has derailed on the West Coast main line at Bletchley leaving no services running between London Euston and Milton Keynes.

There are major delays for rail passengers with London Midland, Southern and Virgin rail services all affected.

London Midland has advised passengers not to travel as all lines are blocked.

However, tickets are being accepted on Chiltern, East Midlands and First Capital Connect services.

Network Rail had initially hoped two of the four lines would be cleared by "early" afternoon, but at 15:30 GMT work was still continuing to repair damage to the tracks.

Driver injured

The Freightliner engine, being operated on behalf of Virgin trains, derailed at Bletchley south junction shortly before 02:30 GMT.

The driver was the only person on board and is being treated for injuries.

The engine was not pulling any freight or carriages.

Media playback is unsupported on your device Media caption One passenger, who gave her name as Christine, was delayed on her way to a funeral in Scotland

The engine is upright but blocking the line, and damage to the running tracks and overhead power lines has been reported.

The Rail Accident Investigation Branch is conducting an investigation.

Robin Gisby, from Network Rail, said that although they hoped to clear two of the lines later, services would still be affected.

"It is likely that severe disruption will continue for the remainder of the day as we work to repair the more significant damage," he said.

"Unfortunately there is quite substantial damage to the tracks and overhead lines."

Engine 'on loan'

Southern services are only running between Croydon and Watford Junction, Virgin and London Midland services are not running south of Milton Keynes, but London Midland is running between Bletchley and Bedford.

Nicola Moss, from London Midland, said: "We do strongly advise passengers not to travel if at all possible.

"But anybody who can get to Bedford for First Capital Connect services or over to Wellingborough for East Midlands Trains services or west to Aylesbury for Chiltern Railway Services, can use our tickets on those trains.

"Network Rail and the freight company are working really hard to get the line clear but that is unlikely to be before lunch time."

A spokesperson from Virgin Trains said the engine was on loan to the company in order to haul some of its older trains.

Passengers are being advised to consult National Rail Enquiries if they intend to travel.