Avanti West Coast reported the fault earlier on Tuesday, adding some lines were blocked and that it could cause delays and cancellations.

The West Coast Main Line is one of the most important railway routes in the UK, connecting London and Glasgow to other major cities including Liverpool, Birmingham and Manchester.

Many trains travelling from London to destinations further north were facing severe delays on Tuesday evening, with one service to Manchester Piccadilly behind by 152 minutes.

Some trains travelling southbound were also delayed, would not stop at certain stations, terminated early or were fully cancelled due to the failure.

Services operated by London Overground and London Northwestern Railway were also affected.

Network Rail apologised for the incident and said it had "identified the signalling issue" preventing Euston from using some platforms.

It added: "It means we can open more that are not impacted. We'll be working with our train operators to gradually increase the number of trains as we reopen them."

Explaining the nature of the fault, a Network Rail spokesperson said: "Our signalling system is designed to put signals to red if it detects a problem, a kind of safety 'fail-safe', and has done so on some of the tracks approaching the station this afternoon.

"We're working with operators to run trains on the lines and platforms that are working as normal, but there are delays and cancellations as a result."

They advised passengers to check with operators before travelling to and from Euston.

Avanti offered concessions to passengers following the inconvenience, including lifting advance and off-peak ticket restrictions for the day across the network.

It said passengers delayed by 15 minutes or more at their destination station would be entitled to its "Delay Repay" scheme, provided they claim within 28 days from the date of travel.

One affected passenger, Sarah O'Connell, who was travelling to Llandudno Junction in Wales reported on X being stuck at Preston for more than 45 minutes.

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Meanwhile, Paul Carroll said he had been "stuck on a train for two hours not moving".

One passenger, concerned about losing his reserved seat, posted on X and Avanti responded: "Trains are expected to be busier than usual. I would suggest grabbing any available seat for your journey today."

The disruption comes after Euston did not operate long-distance services between Good Friday and Easter Monday for engineering work, which included renewing the track between the station and Milton Keynes.