The company was forced to take the same action earlier this month.

Rail users will be facing disruption over the next two days with one provider cancelling “the majority” of services in the region.

Transport for Wales says that the predicted temperatures mean it will be too hot for its older trains to run.

As a result it said it would be cancelling most of its services between Shrewsbury and Birmingham.

The company normally runs eight services a day between the stations - also stopping at Wellington, Telford Central, Wolverhampton and Sandwell and Dudley.

A spokesman said that the final service between Shrewsbury and Birmingham will run as planned on the days.

The company took the same action on Sunday and Monday, August 2 and 3.

It said an arrangement has been reached with West Midlands Railway, which operates on the same line, to accept Transport for Wales tickets for journeys between Shrewsbury and Birmingham on both days.

A spokesman for TfW said: “The majority of TfW services between Shrewsbury and Birmingham will be cancelled on Wednesday 12 and Thursday 13 August due to the forecast high temperatures and Amber weather warning.

“We’re unable to run our older trains during periods of very high temperatures due to on-going failures with the air conditioning systems of our legacy fleet.

“We are working with our supply chain to resolve this as soon as possible, before our older trains are replaced as part of our £800m investment in brand new trains.

“Ticket acceptance has been agreed with West Midlands Railway for journeys between Shrewsbury and Birmingham.

“We apologise for any inconvenience caused by this disruption.”