IT was Mark Twain who credited Benjamin Disraeli with coining the famous phrase “there are lies, damned lies, and statistics”, though it might have been the Duke of Wellington or a Scotsman, Prime Minister Arthur Balfour.

Whoever it was might well have added “and ScotRail performance figures”, for an unseemly spat has erupted between the SNP and the Scottish Labour Party over the alleged failure of Scotrail trains to run on time, or even five minutes late.

The argument is all about Dutch-owned Scotrail getting people to their destinations on time, and the Scotrail Alliance might have picked a better day to be involved in such a public row, given the chaos on some parts of the network in Central Scotland yesterday – see below for details.

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Back to the spat, however. On Monday, Labour’s transport spokesman Neil Bibby was quoted as saying that Scotrail trains were missing their Public Performance Measure (PPM) for prompt arrival at 60 per cent of stations – PPM being the target figure given by the Scottish Government to operator Abellio when it won the franchise that began on April 1, 2015.

Bibby’s exact quote was: “It is unacceptable that services at nearly 60 per cent of stations failed to hit the performance target last month.”

His leader Kezia Dugdale followed that up in her newspaper column by saying “ScotRail trains are failing to meet the punctuality targets at nearly 60 per cent of stations”.

Those statements are not correct. They were based on Scotrail’s own figures, which show that over a rolling 12-month period – not “last month” – some 43 out of 73 stations did not meet the target of 90.8 per cent of trains arriving within five minutes of the scheduled arrival time, as the PPM allows that five-minute grace period.

The problem for Labour is that ScotRail only published the figures for terminal stations, which constitute only about 20 per cent of the entire rail network in Scotland.

This allowed ScotRail to claim that, actually, last month 93.7 per cent of trains arrived within the PPM period of five minutes.

That Labour “60 per cent of stations” claim also saw the SNP issuing a stinging rebuke. They stated: “In fact, this morning 97 per cent of Scottish trains were running on time – three per cent higher than the UK average.”

SNP MSP George Adam weighed in: “Labour have a long and shameful history of making statistics up to try and score cheap headlines – but this blatant attempt to smear an improving rail service shows that they still cannot be trusted.

“We know our rail network is not always perfect – and we’re the first to accept fair criticism when it’s due – but when the service is improving, Scotrail staff deserve credit and support. It is unacceptable that Labour made these false claims in the first place, but it is completely inexcusable that party leader Kezia Dugdale repeated them after they had been proven to be incorrect.

“The Scotrail staff who have worked so hard to improve this service deserve an apology from Kezia Dugdale and from Scottish Labour – and perhaps also an acknowledgement that services have improved significantly in recent months.”

Labour were not having any of that. A Scottish Labour spokesperson said: “This is downright desperation from a political party that has consistently misled voters and has failed to stand up for Scotland’s exasperated railway passengers.

“We make absolutely no apology for standing up for Scotland’s passengers, scrutinising ScotRail’s performance, and demanding improvements. SNP ministers should stop apologising for Abellio to cover themselves for failing to deliver the world-leading contract they promised.

“The time has now come for the SNP to publicly apologise to the thousands of rail passengers who are fed up with delayed, overcrowded and over-priced trains. Rather than trying to spin their way out of their own mess, SNP politicians should spend their time focusing on delivering results for passengers.”

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In any case, ScotRail really did hit trouble yesterday. A signalling issue at Haymarket led to reduced services from Edinburgh to Glasgow, Edinburgh to Helensburgh, and Edinburgh to Dunblane. An issue with the track at Newbridge Junction, near Ratho, was also causing trains to run slower than normal.

A ScotRail Alliance spokesperson said: “We are doing all we can to keep customers moving,” added that anyone delayed by more than 30 minutes could claim compensation.

So now it’s lies, damned lies, statistics, spinning and excuses.