As commuters return en masse after summer holidays next week, the political omens – and the data – afford some hope that a new Labour government may change rail for the better. Say what you like about Gordon Brown, but at least he made the trains run on time.

Analysis of official statistics throughout the tenure of the last seven prime ministers show that punctuality was highest, on average, under the last Labour PM in power.

The public performance measure (PPM) for punctuality, published every four weeks by the industry, measures trains as punctual if they arrive within five minutes of schedule for commuter services, or within 10 minutes for long-distance trains.

As an average, the PM with the best PPM was Brown, with punctuality of 90.5% during his 2007-10 premiership.

Train punctuality remained high in the early years of the coalition government but faded from 2013, enough to make David Cameron’s 2010 to 2016 tenure marginally second best.

Timekeeping has been on a downward path ever since, with Theresa May’s years in charge coinciding with the 2018 timetable fiasco and associated disruption. Under Rishi Sunak, only 85.5% of trains ran on time and many more failed to run at all, with reduced schedules and advance cancellations, partly due to strikes and the national pay dispute that rumbled on during his watch.

The early part of Boris Johnson’s premiership had record periodic highs for punctuality – albeit in a time when services were reduced due to the pandemic and the rail industry could more or less run trains unencumbered by people commuting or travelling.

The record-breaking four-week period when 97.2% trains ran on time came in April 2020, much of which Johnson spent in hospital with Covid, allowing Dominic Raab, briefly de facto acting PM, to claim a share of the glory. As it was the height of lockdown, there were, however, virtually no passengers onboard.

The lowest average and lowest periodic figures were recorded under the premiership of Tony Blair, who inherited Railtrack, the newly privatised railway infrastructure manager that was blamed for some of the worst disasters in UK rail history. Punctuality fell to 57.4% in late 2001, with speed restrictions following the Hatfield crash. It had returned to above 90% in Blair’s last months in office.

The rail historian Christian Wolmar said of the figures: “It probably reflects the decline in investment over the last decade. And given Sunak barely even took the train, and with a transport secretary more interested in the culture wars than running the trains on time, it’s not surprising things have got worse.

“It’s not going to be easy for Keir Starmer to reverse that, but the first thing to do is sort out the industrial relations.”

Starmer’s government appears to have settled the long-running pay dispute with drivers, pending a ballot of Aslef members, although the threatened strikes at LNER, now suspended, suggest it may not be entirely smooth. Labour meanwhile announced immediate legislation to nationalise train operations and set up the state-owned Great British Railways. No official data is yet available for Starmer’s time in office.

Industry body the Rail Delivery Group said it measured performance via changes in the annual average figure from the regulator, which was highest at 93.4% in 2020-21, when fewer trains ran during Covid and less than a quarter of the normal passengers travelled.

A spokesperson said: “We know how important reliability and punctuality is to customers. Train companies work hard to maintain as many services as possible, but delays can occur due to various factors, like weather and flooding, industrial action, infrastructure issues such as track or signalling faults, train faults and external incidents such as trespass.”

They added that “a number of cross-industry groups are working to find solutions to some of the main reasons why trains are delayed”.

A Department for Transport spokesperson said: “The secretary of state has been clear that rail performance across the country is at an unacceptable low.

“We will take all operators into public ownership alongside bringing track and train back together, to make sure our railways work properly and in the interest of passengers. And we will tackle longstanding staffing issues by taking a grown-up approach to industrial relations.”