Local train users are being advised to only travel if ‘absolutely essential’ during this week's amber-alert heatwave.

The announcement was made yesterday when Network Rail said the current record-breaking temperature are likely to cause travel disruptions throughout south Wales.

The latest travel warning has come from Network Rail, which has warned of travel disruption across Wales and England due to the weather.

"Our advice to customers is to only travel if absolutely essential, and to expect a very reduced train service and delay,” said Network Rail spokesperson Jake Kelly.

Damage limiting measures such as temporary speed restrictions have been in place across the TfW network since Sunday as a result of the high temperatures while alolng the east coast mainline in England, Network Rail has had to cancel trains altogether.

Mr Kelly went on to say that this ‘all new territory’ for rail companies and they are managing the situation as best as they can.

"We haven't taken any of our decisions lightly, but we've not been faced with these exceptional temperatures before,” he said.

“We're spending hundreds of millions of pounds a year on making the railway more resilient but ultimately faced with weather like we've never faced before, the infrastructure will suffer so we've had to put in place arrangements."

Looking ahead to the rest of the week, Mr Kylly said he hoped to run a full service on Wednesday and beyond.

“But that that will depend on the damage that the weather does to the infrastructure over the next couple of days. We have lots of plans in place to make sure that we can run."