Passengers should travel only if absolutely necessary on Thameslink due to a strike by RMT members at Network Rail and UK train operators this week. The strike days are Thursday (August 18) and Saturday (August 20) – but commuters will also be affected in the mornings after on Friday (August) and Sunday (August 21). On Thursday and Saturday, Govia Thameslink Railway (GTR) will be running the same service plan as for the last strikes in July and warns there will be very few trains, with crowding expected, particularly on first and last trains. St Pancras International and Bedford Two trains per hour will run between St Pancras International and Bedford, calling at St Pancras International, West Hampstead Thameslink, St Albans City, Harpenden, Luton Airport Parkway, Luton, Leagrave, Harlington, Flitwick and Bedford only. Gatwick Express will not operate although the airport will have a limited Thameslink service. There will be no service at all on many lines south of London. Trains will start running at around 7.30am and finish between 4.30pm and 6.30pm. However, passengers need to check what this means for their journeys as first trains may not reach stations until considerable later than usual and last trains will end much earlier than usual. Services will also start later the morning after each strike, with an amended Sunday service set to run on Friday. Morning trains are likely to be very busy. Customers are recommended to travel later, plan their journeys and check again before travelling. Online journey planners such as nationalrail.co.uk will be updated at the weekend for Thursday 18 August and Friday 19 August and early next week for Saturday 20 August. Sunday 20 August is live now but amendments will be made to first trains in the coming days. Strike action by the drivers’ union ASLEF at neighbouring train operators is also likely to affect services on Saturday. Andrew Haines, Network Rail chief executive, said: “It saddens me that we are again having to ask passengers to stay away from the railway for two days next week due to unnecessary strike action, when we should be helping them enjoy their summers." Visit here for more details