Heathrow Express plans to run services every 15 minutes during shortened operating hours if a threatened 24-hour walk-out by Network Rail workers goes ahead from 17:00 on Bank Holiday Monday.

Should the RMT and TSSA unions’ strike by signallers and maintenance staff take place, on Monday the normal Heathrow Express timetable will be in operation until 18:30, and on Tuesday services will run between 07.30 and 18:30.

Trains between Heathrow terminals are also set to finish at 18:30 on Monday and run only between 07.30 and 18:30 on Tuesday.

Outside of these times, transferring passengers are advised to use the London Underground or bus services.

Should the strike go ahead, the Heathrow Connect stopping service between Paddington and Heathrow will not run at all on Monday and Tuesday next week.

Keith Harding, operations director for Heathrow Express, said: “Our advice to customers using the Heathrow Express on Monday and Tuesday is to check before you travel.

“The situation is constantly evolving so you can get the latest information on our website, heathrowexpress.com, and Twitter @heathrowexpress.”