Commuters travelling from Corby, Kettering and Wellingborough to Bedford or Luton during peak times will be forced to use a coach service until 2020.
The changes, which will come into force on May 20 next year, will see an half-hourly bus service run from Wellingborough to Bedford, with southbound trains which arrive in London between 7am and 10am no longer stopping at Bedford or Luton.
In the evening peak time rush, no trains leaving St Pancras between 4pm and 7pm will stop at Luton or Bedford – meaning people working in those two towns will have to get a coach back to Wellingborough.
Chairman of the Leicestershire and Northamptonshire Rail Action Committee (LANRAC) Christopher Groome said the timetable change was ‘disappointing’.
He said: “I know why they’re doing it but I am very disappointed.
“There will be a whole group of passengers that are affected by this.
“Personally I think that travelling by bus and train is not comparable.
“Trains are quicker and far more convenient.”
Commuters travelling from the north to Luton will have to get a bus from Wellingborough to Bedford and then join the Thameslink line to Luton.
Off-peak services and Luton Airport Parkway services will not be affected by the changes.
Ben Foley, from the East Midlands Rail Campaign, said: “It is outrageous for the Government to conduct a consultation, when even before they have finished analysing the results, they implement some of the major changes they pretended to be consulting about.
“Supporters of the East Midlands Rail Campaign will be working hard to make sure the Government doesn’t get away with this disgraceful behaviour.
“We will be right behind our campaign members who currently commute into Bedford and Luton from the north each day, who will be really hard hit.”
The changes are being brought about as part of a £7bn upgrade of the Thameslink line which will see more trains needing to operate on the shared network between Bedford and London.
These changes will be in place until the completion of the Midland Main Line upgrade programme in 2020.
Any monthly or annual season ticket holders using the replacement coach service will be eligible for a 50 per cent discount on their season ticket.
Managing director at East Midlands Trains Jake Kelly said: “Major investment is being made to improve the railway in Bedford and the surrounding areas, with the £7bn Thameslink programme and the transformation of the Midland Main Line which will deliver the biggest upgrade of this line in almost 150 years, bringing better journeys for customers and representing an investment of more than £1bn.
“To enable these major projects to be successfully completed, there will have to be some changes to our timetable and we appreciate that this will mean inconvenience for some of our customers.
“Our priority has been to ensure that these customers have alternative transport connections in place with the replacement coach service from Wellingborough and season ticket discounts for those using the coach.
“In the longer term, we will continue to work with the Department for Transport and Network Rail to deliver the improvements needed for the Midland Main Line which will provide greater capacity on the network and therefore enable future timetable improvements.”
Managing director for Network Rail’s London North Eastern and East Midlands route Rob McIntosh said: “We are currently carrying out the biggest upgrade of the Midland Main Line since it was first built in 1870 with an investment of more than £1bn that will create a bigger, faster, more reliable network which will bring significant, long term benefits the economies and communities our railway serves.”
A copy of the new timetable will be available during February 2018.
EDITOR’S NOTE: An earlier version of this story reported that the replacement bus service would run hourly, rather than half-hourly. This was based on incorrect information provided by East Midlands Trains, who have apologised for the error.