Train companies are penalising passengers with 'sneaky' fare changes which start today, an MP has claimed.
Rail operators across the country put ticket fares up at the weekend as part of their annual round of price increases.
London Midland, which operates services from Northampton to Birmingham and Northampton to London announced its fares would go up by an average of three per cent on unregulated fares, which are mainly off-peak.
The increase is modest compared to some train companies, but members of Northampton's Rail Users' Group have spotted other changes to the designated peak times for travellers to the capital, which they say could catch some passengers out.
Changes to weekday ticket restrictions mean if people travel during the late afternoon or early evening, they will need to hold a season, any-time or any-time day ticket, or face a surcharge.
It means passengers will be affected if they leave London Euston for Northampton between 4.45pm and 6.45pm, without one of the advanced tickets
Sally Keeble, Labour's MP for Northampton North and chairman of the rail users group, criticised the change and pledged to write to the rail company.
She said: "This is actually a sneaky fare increase on people travelling to Northampton.
"People going out for the day will be the ones most affected because they won't have season tickets.
"Someone missing their earlier train is now in for an extra charge. And anyone wanting to take their children to London for the day either has to cut the trip short or keep them occupied until 6.45pm to avoid an extra cost.
"I will certainly be contacting London Midland to object."
The changes have come about after London Midland created a new 'evening peak period' which covers the times when trains are busiest.
Mrs Keeble said the change also followed increases in parking charges at Northampton's Castle Station, which commuters are unable to avoid as scheduled buses arrive too late for passengers to catch the most popular morning rail service.
Advice on the company's website said: "If you want to continue paying off-peak fares you will probably need to vary your travel time by less than an hour."