Commuters from Streatham and Tulse Hill stations are facing transport chaos travelling in to work this week because of a driver pay dispute.
A skeleton Thameslink service in to central London through rush hour means many train users will need to find alternative routes, or face the prospect of not fitting on packed trains.
Roughly one train will travel an hour from Streatham -one of the worst hit stations on the route - with only a marginally better service from Tulse Hill.
The reduced service is a result of a pay dispute between train operator First Capital Connect (FCC) and drivers.
Drivers are angered by the company's plan to freeze pay this year and offer a minimum 3 per cent rise next year.
They are refusing to do voluntary overtime as a result of the dispute, meaning roughly half of services will be cancelled.
Union Aslef is to ballot its members for strike action meaning rail disruption could worsen in the run-up to Christmas.
From today, trains from Streatham will leave at 6.50am, 7.52am and 8.52am, and there will be a dramaticaly reduced service throughout the day.
Trains from Tulse Hill will depart at 6.56am, 7.56am, 8.05am, 8.39am and 8.58am.
Lib Dem parliamentary candidate Chris Nicholson said: "It is completely unacceptable that Streatham and Tulse Hill residents should have to suffer in this way. It seems that Streatham residents are being hardest hit. I urge First Capital Connect and the union to sort this out so that commuters do not suffer."
The dispute has been affecting trains since pay talks began last Thursday.
A FCC spokesman said: "There is a significantly reduced service on our Thameslink route because some drivers are not working rest days and overtime.
"This situation started when pay talks began with our drivers. We are disappointed that the union Aslef has now decided to ballot its members for strike action and apologise to customers for the continued disruption.
"We are working to provide the best possible timetable each day and limit the disruption caused. Talks will continue and we hope for a speedy resolution."
For up-to-date timetable changes visit firstcapitalconnect.co.uk
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