Passengers are suffering a “miserable” service on the new Borders Railway, with more than two in three trains arriving late, campaigners have complained.
Cancellations have added to the disruption on the Edinburgh-Tweedbank line, with seven services not running on one day last week because of faulty trains.
Supporters of the route blamed the poor punctuality on ScotRail using its least reliable trains, along with cutbacks to the length of double track, which hampers trains being able to pass each other.
Only 32.7 per cent of trains arrived at Tweedbank within one minute of time between 18 October and 14 November, the latest ScotRail figures show, down from 33.1 per cent the previous month.
Rail consultant David Spaven said: “This is a miserable service record. Day-to-day performance has varied widely, particularly in terms of cancellations and trains missing out stops to catch up time.
“This is not an acceptable quality of service. [Scottish Government agency] Transport Scotland was warned years ago by rail industry insiders and railway campaigners that cutting back on the amount of double track would be a foolish economy, and so it has proved.
“It should at the very least look at hiring better-performing trains to minimise the damage to the patronage and reputation of the Borders Railway.”
Allan McLean, chairman of the Campaign for Borders Rail, said the line had attracted large numbers of passengers “but it is disappointing cancellations and delays have marred performance on some days”.
The ScotRail Alliance, which includes track owner Network Rail, said punctuality had been hit by factors such as trains stopping longer at stations because of “larger than anticipated” passenger numbers, train faults and leaves causing slippery rails.
Its spokeswoman said: “There have been some teething problems, but we’ve started implementing plans to address these and provide the best possible service for our customers.”
The alliance said the percentage of trains arriving within five minutes last month increased by 7 per cent to 85 per cent.
Transport Scotland said punctuality was important and it was working with ScotRail to maintain “high standards”.