Rail commuters face an increase in season ticket costs next year of almost 3%.

The cap on the annual rise in regulated fares is linked to July’s rate of Retail Prices Index (RPI) inflation, which was announced by the Office for National Statistics as 2.8%.

Rail campaign groups warned that commuters will “refuse to pay” if season ticket prices continue to be hiked.

They have also called for the lower Consumer Prices Index (CPI) measure of inflation to be used to set fare increases, which are implemented from January 2 2020.

The CPI rate increased to 2.1% last month, the ONS said.

The UK, Scottish and Welsh Governments regulate rises in around half of fares, including season tickets on most commuter routes, some off-peak return tickets on long-distance journeys and tickets for travel around major cities at any time.

A cap on how much they can be increased is pegged to the July RPI figure, except for off-peak fares in Scotland for which RPI-1% is used.

Rail regulator the Office of Rail and Road said regulated fares went up by an average of 2.8% in January 2019, following the July 2018 RPI figure of 3.2%.