ScotRail's performance level is at its lowest since the franchise began, according to latest figures.

An official report published by the company showed 81.8% of services were on time between September 16 and October 13.

It comes as a freedom of information request revealed ScotRail's performance benchmarks had been waived until June 2019 by Scottish Transport Secretary Michael Matheson.

The waiver included the caveat that "any further drop-off in performance will be unacceptable".

The figures also put ScotRail's Moving Annual Average for punctuality at a franchise low of 87.5%, below the agreed breach level of 88.22%.

ScotRail was fined more than £2.2million for performance breaches in the first half of 2018.

Among those who have complained about a below-par service are passengers using ScotRail services between Barrhead, Neilston and Glasgow.

Recent analysis by Transport Scotland showed that the ninth most overcrowded train journey in Scotland was the 5.27pm Glasgow Central to Barrhead service, running at 109 per cent of planned capacity.

The eighth most overcrowded was the 7.56am service from Glasgow Central to Barrhead, which was also running at 109 per cent of capacity, and the sixth most overcrowded was the 4.35pm Glasgow Central to Neilston train, running at 112 per cent of capacity.

Meanwhile, the 8.07am train from Neilston to Glasgow Central, which was the third busiest service in 2017, actually moved up the list in 2018 to become the second-most overcrowded rail journey in the country, running at 123 per cent of capacity.

Scottish Labour has now called for the reinstatement of franchise benchmarks and for Scotland's railways to be brought back into public ownership.

The party's transport spokesman, Colin Smyth MSP, said: "It is little wonder performance is plummeting after the SNP gave ScotRail a licence to fail until June next year.

"Far from being punished for their failings, ScotRail are being let off the hook.

"Enough is enough - passengers deserve better than the contempt being showed to them by ScotRail and the SNP Government."

ScotRail Alliance managing director Alex Hynes said significant disruption was caused by strong winds during Storm Ali in September.

He added: "Everyone at ScotRail and Network Rail worked flat out to keep people moving and to get services returned to normal as quickly as possible.

"We are investing billions in improved infrastructure and hundreds of millions of pounds on new and upgraded trains as we continue to do everything we can to improve performance.

"It's part of our plan to build the best railway Scotland has ever had."