SCOTRAIL’S annual performance has plummeted as it was revealed scores of commuters are so fed up with train services they have written to Nicola Sturgeon demanding something is done.

Figures show the operator’s public performance measure (PPM) – which takes in cancellations and trains more than five minutes late – sunk to 87.4 per cent across the last financial year, below the 92.5% target and in breach of its contract.

It is the worst annual performance recorded by the franchise under Abellio’s watch, after the Dutch-owned firm took over in 2015.

Scottish Labour’s transport spokesman Colin Smyth said thousands of travellers were being let down every day.

He said: “Performance levels are falling but rail fares are rising. Despite promises of improvement from ScotRail, and the Transport Secretary, things are getting worse not better.”

It came as the Scottish Tories released a series of Freedom of Information responses showing that, in the space of just two months last year, 83 people wrote to Ms Sturgeon and Transport Secretary Michael Matheson insisting they were “scunnered” with the “abysmal” train service.

Detailing a catalogue of delays, cancellations and overcrowded trains, the emails – some from SNP supporters – outline the scale of public frustration with the railways.

One correspondent insisted it was like going back to “the dark ages”, while another said: “ScotRail are making false promises and apologies from them are worthless.”

Another said their seven-year-old grandson and two other young children had been trampled on and crushed because of severe overcrowding on an Edinburgh to Dundee train following a rugby match.

A message from a commuter on the Milngavie line said: “Every single day the trains are late, cancelled, dangerously overcrowded or all three.”

The emails were received in November and December last year.

Scottish Tory transport spokesman Jamie Greene said they “highlight the devastating effects of Scotland’s appalling train service on the travelling public”.

He added: “Commuters are regularly subjected to late, cancelled and overcrowded trains at an extremely high financial and personal cost.

“It is astonishing that the SNP government is still failing to ensure that travellers receive a decent service.

“Despite these letters, and the myriad reports of ScotRail failing to reach its targets, Nicola Sturgeon’s government has done nothing to improve train travel in Scotland.”

The First Minister previously said ScotRail is in the “last chance saloon” and could be stripped of its contract if it fails to improve.

A Transport Scotland spokeswoman said it was “wholly understandable that many passengers are unhappy with ScotRail’s performance, particularly in the east of the country”.

She said: “As has been stated many times, including at First Minister’s Questions this week, ministers fully expect performance to improve at the earliest opportunity to meet franchise and regulatory targets, and that can only be achieved by delivering strong performance now – ScotRail has been made aware of the necessity for them to meet these expectations.

“If ScotRail does not deliver its contractual commitments in the remedial agreement, it runs the risk of the franchise being terminated early.

“ScotRail recently committed an extra £18 million to improve improvements for customers to tackle train crew and train fleet challenges, along with initiatives to support performance improvement.”

A ScotRail spokesman said: “This has been a challenging time for Scotland’s railway, but things are improving. More trains are arriving on time than ever before, and everyone at the ScotRail Alliance is working flat out to provide customers with the service they deserve.”