A potential 5.5 per cent rise in England’s train fares next year has been described by public transport groups as ‘outrageous’.

July’s Retail Prices Index (RPI) measure of inflation – which is often used to determine increases in the cost of train travel – will be announced on Wednesday.

The Government has not confirmed how it will determine the cap in regulated fare rises for 2026, but this year’s 4.6 per cent hike was one percentage point above RPI in July 2024.

Banking group Investec has forecast this year’s July RPI figure will be 4.5 per cent, which means fares could jump by 5.5 per cent.

Bruce Williamson of pressure group Railfuture said ‘it would be outrageous’ if fares rose by that much. He added: ‘What would be the justification for jacking up fares above inflation? There isn’t any.