A passenger stranded at Luton Airport this afternoon has reported that some 30 flights have not taken off as scheduled, leaving hundreds of passengers in the departure lounge.

The airport alerted customers shortly after 4.20pm that it had suffered a “runway defect” - thought to be to do with the tarmac - caused by the extreme temperatures, which have hit 37 Celsius in the area.

Alison Cybe wrote: “Hundreds of passengers, myself included, stranded at Luton Airport as over 30 flights delayed indefinitely now due to runway melting in extreme high temperatures.”

Luton Airport has said engineers are inspecting the problem and they hope to have services up and running again by this evening.

TfL has advised that as of 4.30pm today, the following services are affected by the hot weather:

• A part-suspension on the London Overground between Romford and Upminster and between Willesden Junction and Richmond with minor delays on the rest of the line
• A part-suspension on the Metropolitan line between Baker Street and Aldgate with severe delays on the rest of the line
• The Hammersmith & City line is suspended
• There are severe delays on the Bakerloo, Central and District lines (with no service between Parsons Green and Wimbledon due to a signal failure), and on Tram services (due to a shortage of trams)
• There are minor delays on the Elizabeth, Jubilee and Piccadilly lines
• The London Cable Car is currently suspended

There is currently a good service on the Circle, Northern, Victoria and Waterloo & City lines, and the DLR.

A Spanish commuter has posted dramatic video of a local train surrounded by wildfire flames in the province of Zamora, in Castile and Leon in the west of Spain.

Francisco Seoane Pérez tweeted: “Moments of panic on the Madrid-Ferrol train at Zamora-Sanabria, 9:30 a.m. The train continued the journey after a few minutes stopped.”

Passengers appear alarmed as the flames leap several feet in the air above the treetop, with blazes visible on both sides of the carriage.

Flights have been suspended at Luton Airport, due to a runway defect linked to today’s high temperatures.

A statement posted to the airport’s Twitter account shortly after 4.20pm reads: “Following today’s high temperatures, a surface defect was identified on the runway.

“Engineers were called immediately to site and repair works are currently in progress to resume operations as soon as possible.

“We would like to apologise for the inconvenience caused.”

Nine incoming passenger flights have so far been diverted – mainly to nearby Stansted.

Read the full story:

Rail travellers on Merseyside who are obliged to travel on Tuesday may end up on buses instead.

Merseyrail says: “Due to Network Rail imposing speed restrictions in response to the extreme heat, Hunts Cross to Southport line trains are starting and terminating at Liverpool South Parkway.

“Rail replacement buses are running between Hunts Cross and Liverpool South Parkway stations in both directions.

“These timetable changes will remain in place until the end of service on Tuesday.

“Any passengers who are feeling unwell while on a train should get off at the next stop and request help from station staff. Water will be available at all staffed stations for passengers who are feeling unwell.”

Zoe Hands, chief operating officer at Merseyrail, said railway workers will be checking the temperature of the rails: “We have staff in place on the rails to monitor the temperature of the steel as each train passes. If the temperature gets too hot, we may reduce the speed of the train through that section to 20mph.

“These measures ensure our network is as well prepared as possible to face the unprecedented temperatures that we expect to see this week. We would however advise that customers only travel if necessary.”

The Met Office is predicting that Tuesday will see Liverpool’s highest-ever recorded temperature. The current record is 34.5C, recorded in August 1990. The temperature on Tuesday is expected to reach 36C.

The mercury is rising - and, with it, the chance that your train will be delayed or cancelled.

On Monday and Tuesday, as temperatures are set to soar and potentially hit 40C in the UK, train operators are reducing services to cope with the heat.

So what does it mean for your imminent public transport journeys? And are you still allowed to travel by train?

Our expert Simon Calder will be on hand tomorrow, Tuesday 19 July, to answer all your questions in an ‘Ask me anything’ event between 4-5pm.

Click here to post your travel question

Monday lunchtime at London St Pancras International was busy when Simon Calder recorded his daily podcast for The Independent.

“There seem to be an awful lot of people here at St Pancras,” he reports. “And I’ve seen loads across the road at King's Cross who have not be deterred by the ‘do not travel unless absolutely necessary’ line.

“Clearly a lot of people would say, ‘It’s for me to say whether my journey is absolutely necessary or not’.”

Eurostar trains from London to Paris are returning to normal. There was widespread disruption during the morning due to vandalism on the high-speed line north of the French capital.

The cross-Channel train operator is telling passengers: “It will be very hot over the next few days in all Eurostar destinations. Remember to bring plenty of drinks for your journey. There are no 100ml liquid restrictions with us.”

Click here to listen to the podcast

Rail services across the UK are expected to return to normal on Wednesday after the heatwave speed restrictions and line closures.

In Scotland, the trains will actually be far better from 20 July onwards than they were last week. The emergency timetable, in place since 23 May, will end – with 700 services per day restored.

Around one-third of daily trains were axed because train drivers exercised their right not to work overtime. Evening services were especially hard hit.

The drivers’ union, Aslef, has been in dispute over pay. But earlier this month members voted to accept an improved pay offer made by ScotRail.

The train operator said: “We've been relying on drivers working overtime or on their rest days to run a normal timetable, as the pandemic meant that training new drivers was significantly delayed.

“Without Covid and that impact on training, we would have trained around an extra 130 drivers today.

“Our train planning team are working flat out to carry out the changes required for the near 700 services to be reintroduced. This includes scheduling the movement of trains to where they need to be, with rosters for on-train staff and schedules for drivers being altered.

“If you’re planning to travel from Wednesday, 20 July, please see our normal timetables.”

Amid widespread cancellations, delays and slow-moving trains due to the mid-July heatwave, commuters and holidaymakers are also having to work around various train strike dates over the course of summer.

The next industrial action dates are 27 and 30 July - the former is a nationwide rail strike by RMT union members working at Network Rail, while the latter involves Aslef members at Arriva Rail London, Chiltern Railways, Greater Anglia, Great Western, Hull Trains, LNER, Southeastern and West Midlands Trains as part of an ongoing dispute over pay.

Travellers heading off by train during August won’t escape the strike disruption, either - staff working for Network Rail and 14 train operators will walk out on Thursday 18 and Saturday 20 August.

Further walkouts will affect trains on 17, 19 and 21 August, too, drastically curtailing services over one of the busiest weekends of the year across Great Britain.

Simon Calder has the full story:

Train journeys could double amid heatwave temperatures on Monday and Tuesday, Network Rail’s chief spokesman Kevin Groves told Sky News.

Mr Groves explained that trips which usually take two hours could take “more than four hours” amid fears around rails “buckling” in the extreme heat.

He told presenters that heat restrictions on UK trains would continue until around 8pm tonight, and reiterated the organisation’s warning to only travel by train if absolutely necessary during Monday and Tuesday.

“Certainly later on today that (buckling) is a strong possibility, which is why, from about midday today through till 8pm tonight, there will be large swathes of England and Wales that will have emergency heat-related speed restrictions placed on the rail network,” he said.

“Our advice to passengers if they can, today and tomorrow, is only travel if it’s really necessary; otherwise try and shift your arrangements to later in the week and you’ll get a full refund,”