ScotRail bosses have admitted they do not expect trains to hit punctuality targets for another two years.
The train operator estimates it will be 2021 before it reaches the target of 92.5 per cent of services running on time.
And a review commissioned by regulators to assess how ScotRail was doing warned it faces “significant challenges” in meeting the target.
ScotRail does expect improvements by March, but Scottish Labour’s transport spokesman Colin Smyth accused it of failing passengers while hiking fares and said Transport Secretary Michael Matheson had “turned a blind eye” to ongoing problems.
Mr Smyth said: “The truth is this failing franchise has never met its performance target and no one now seriously believes they ever will, even by 2021.
“Michael Matheson has turned a blind eye to ScotRail’s appalling record of failure and left passengers to suffer delays, cancellations, overcrowding and yet another hike in fares.”
Despite continued criticism, ScotRail forecasts it will pull off its biggest performance improvement for nearly a decade by finally hitting punctuality targets in two years’ time.
The key measure is currently 87.3 per cent but the train operator predicts it will reach the required 92.5 per cent by March 2021.
Such a rapid a turnaround has not been seen on Scotland’s railways since 2011-12 while ScotRail has also not achieved annual performance of 92.5 per cent since 2013. The measure is known as the moving annual average – the proportion of trains arriving at their destination within five minutes of schedule over the last 12 months.
Industry experts and politicians are sceptical that reaching 92.5 per cent will be achieved in two years.
However, ScotRail is understood to be confident following a series of improvements to cut track and signalling fault delays and is close to completing the training on newly acquired trains and routes that caused 60 cancellations a day. Ministers have ordered a remedial plan be submitted by next month to cut the cancellations.
Last month, a report for the Office of Rail and Road regulator by assessors Nichols on ScotRail’s last improvement plan, concluded that there had been a further decline in performance.
A spokeswoman for Transport Scotland said: “We fully expect ScotRail to submit a robust remedial plan that gives them every opportunity to achieve this target at the earliest opportunity.”
A ScotRail spokeswomen said: “Actions from the Donovan review have been praised in the Nichols report, and these actions have seen the banning of skip-stopping except as a last resort and improvements in train reliability.”
She added: “But our performance is not where we want it to be, and as this year progresses our customers will see improvements.”