Delays have blighted rail travel in the north and north east over the past six months, new figures have revealed.
Scotrail’s own statistics show fewer services are arriving at stations on time despite efforts to boost reliability.
Bosses at Scotrail Alliance accepted its performance was “not where we want it to be” but believe an improvement plan will in time deliver “the best railway Scotland has ever had”.
Transport Scotland, meanwhile, says there are already signs of “gradual but consistent improvement”.
North east politicians have, however, raised concerns that promises have been broken and that service quality is in fact declining.
The figures appear to show the percentage of services arriving or terminating within five minutes of the scheduled time has dropping when compared with six months ago.
In November, 87.4% of trains were made it into Aberdeen within five minutes of the allotted time, but this has now slipped to 85.9%.
A similar declined has been recorded in Fort William, where last month 87.6% of services arrived within five minutes, compared to 88.7% six months earlier.
The number of services making it into Oban on time also dropped, from 84.4% to 82.7% during the same period.
Last night, a north-east MSP claimed transport chiefs were failing to address the problem.
Aberdeenshire West MSP Alexander Burnett said: “It is disappointing to see that performance has dropped at stations across the north of Scotland, not just in the last six months but again in the most recent month.
“That would suggest that whatever the problem is it is not being addressed.
“The transport minister has previously insisted that Scotrail performance would improve but these figures suggest it is going in the opposite direction.
“This also comes just a day after it emerged that new trains for the line between Aberdeen and Edinburgh will not be delivered on time.
“It is clear that Scotrail needs to up its game and improve services for long-suffering passengers.”
The new statistics come hot-on-the-heels of the publication of a review from former Transpennine Express managing director Nick Donovan, which gave Scotrail Alliance 20 recommendations to improve service.
Scotrail Alliance said: “Performance is not where we want it to be but as this year progresses our customers will continue to see improvements as more of the 20 Donovan performance recommendations begin to support the improvement of the day-to-day running of services.
“We are building the best railway Scotland has ever had and service performance is a huge part of this delivery.
“Everyone at the Scotrail Alliance is working together to deliver these improvements.”
A spokesman for Transport Scotland added: “With their new, more focused performance improvement plan the Scotrail Alliance has an opportunity to deliver gradual but consistent improvement.
“Together with officials at Transport Scotland, the transport minister will be monitoring progress closely.
“It is time everyone got behind the hard-working rail staff up and down the country, both front line and behind the scenes, as they strive to achieve this.”