Members of the Transport Salaried Staffs' Association (TSSA) at CrossCountry began a 24-hour strike from 21:00 GMT on 26 December.

And more TSSA members at Great Western Railway and West Midlands Trains will walk out on Wednesday and Thursday.

RMT union members at Network Rail will resume strikes over pay and conditions on Tuesday 3 and Wednesday 4 January.

Their latest walkout ended at 06:00 GMT on Tuesday - but delays continued into the afternoon as services got back up and running. The late handover of engineering works also caused some disruption, including at Paddington.

Network Rail said the "industrial action means rail travel will be significantly disrupted throughout December and January".

The TSSA strikes are part of a long-running campaign for a guarantee of no compulsory redundancies, no unagreed changes to terms and conditions, and a pay increase which addresses the rising cost of living.

Members at Great Western Railway go on strike from noon on Wednesday to 11:59 GMT on Thursday, and at West Midlands Trains from noon on Wednesday to noon on Thursday.

The strikes involve staff who work in customer service management, driver management, training, control, customer communications, safety, timetabling and planning.

The union said it believes these walkouts will severely affect services at CrossCountry, which run from Penzance to the Midlands, Wales and northern England through to Scottish cities as far north as Aberdeen.

CrossCountry said are no services running north of York. It also warned trains running north of Banbury and services from Reading to Manchester would be "extremely busy".

Adding to the delays for travellers, 1,000 Border Force passport control staff at Birmingham, Cardiff, Glasgow, Gatwick, Heathrow (Terminals 2, 3, 4 and 5) and Manchester airports, went on strike on 26 December and will walk out again from Wednesday to Saturday.

TSSA organising director Nadine Rae that members did not want to strike "but they are sick and tired of being taken for granted".

The Department for Transport had urged unions to "to step back, reconsider and get back round the table, so we can start 2023 by ending this damaging dispute."

A spokesman for Network Rail said: "Passengers should really check before they travel so they don't just turn up at a station for no trains to be there."