Members of the National Union of Rail, Maritime and Transport Workers are walking out on Tuesday (June 21), Thursday (June 23) and Saturday (June 25) in a dispute over pay, job cuts and safety.
Train operators have put in place emergency timetables from Corby, Kettering and Wellingborough stations.
Services will also be significantly reduced on days following action on Wednesday (June 22), Friday (June 24) and Sunday (June 26) as Network Rail claims strike days chosen are “designed to inflict as much disruption as possible” with not enough time between to fully recover a normal service.”
About a dozen commuters got on to the first train at 8.08am to London this morning from Kettering, including Darcie, a student who had to visit the capital for a vital face-to-face meeting.
She said: “I have to get to an appointment at the passport office in London. I made the appointment quite a while ago. I can’t get the last train back so we’ve had to book accommodation but we’re going to make the most of it. We’ll walk around and do things for free.”
She added: "We’re students so we are used to strikes.”
East Midlands Railway Intercity will run one train per hour between Nottingham and London calling at Kettering and one train per hour between Sheffield and London calling at Kettering.
Connect 360 trains will have one train per hour between Corby and London calling at Kettering and Wellingborough.
East Midlands Railway managing director, Will Rogers, called the strikes “wrong for the railway and communities we serve.”
He said: “I would urge all customers to think carefully about their journeys – and make alternative arrangements if possible.”
There will be no direct trains between Luton and London St Pancras on Saturday and Sunday due to pre-planned engineering work.
The industrial action, which has been described as the "biggest rail strike in modern history", involves union members which include railway staff such as guards and signalling operators.