All lines are blocked between London Euston and Milton Keynes this afternoon.

Damage to the overhead electric wires on London North Western railway means trains will not be stopping at Harrow & Wealdstone, Bushey and Wembley Central. Trains heading through Watford junction are also affected.

Train services running to and from these stations will be cancelled, delayed or revised.

Disruption is expected to last until 5.00pm.

Meanwhile trains are also not running between St Albans and London St Pancras due to a safety inspection.

It is underway on the track between West Hampstead Thameslink and St Pancreas. No trains are running in either direction.

Delays of up to an hour are expected.

Travellers are advised to delay their journeys until later if possible.

A Govia Thameslink Railway spokesperson said: “We regret that journeys will be severely disrupted this evening due to damage to the overhead wires on the Thameslink route near West Hampstead.

“Specialist teams from Network Rail and emergency services have been on site dealing with this issue. Until further notice, Thameslink and East Midlands Trains services remain disrupted and will be subject to cancellation and alteration.

“Major disruption is expected to continue until 22:00.

“Thameslink has requested rail replacement buses to be based at key locations such as Bedford, Luton and St Albans to help passengers with their journey.”