CAMPAIGNERS have raised concerns over the “shambolic” track record of the incoming boss of Network Rail in Scotland.

Liam Sumpter, who will take on the newly-created role of chief operating officer next spring, was previously forced to apologise after “rude” exchanges with customers on social media.

He is currently regional director of Northern Rail, which has faced sustained criticism in recent months over delays, cancellations and overcrowding.

More than 20 newspapers across the north of England joined forces this summer to call for the UK Government to intervene and fix their “broken” rail system.

Mr Sumpter will take up his new role at a time of mounting concern over Scotland’s railways, with Network Rail widely blamed for causing delays and cancellations through failures in infrastructure.

Critics have also called on Dutch firm Abellio to be stripped of its franchise to run ScotRail following record lows in punctuality and performance.

Douglas Stewart, associate committee member at Rail Action Group East of Scotland, said customers and wider stakeholders would be “gravely concerned about the appointment of Sumpter to such an important role”.

He said: “At a time when the ScotRail Alliance needs expertise, change and direction – not to mention a real focus on customer service – to overcome what has been an appalling year for reliability and punctuality, you really must question whether he is the right person for the job.”

He said “major question marks hang” over Mr Sumpter’s credentials, and highlighted a row over the rail chief’s “aggressive” Twitter use earlier this year.

In one exchange, Mr Sumpter told a customer his opinions were “pretty much nonsense” and insisted he would block another “so I don’t stumble across his vile idiocy again”.

He wrote to one passenger: “As for profit and subsidy, I’m sorry to say your grasp of the basics is so, so limited that you should probably go and research it if you want to understand it better.”

Mr Sumpter later apologised and said the responses, sent from his personal account, were “not appropriate and fell short of the way we try to help customers”.

Scottish Labour’s transport spokesman Colin Smyth said it was “little wonder people are asking whether he is the most suitable person for this job”.

Mr Sumpter will replace David Dickson, whose role as ScotRail Alliance’s infrastructure director is being replaced by the chief operating officer post.

A Network Rail spokesman said: “Liam Sumpter is a highly-experienced railwayman who has worked across a wide range of operational, commercial and infrastructure maintenance posts.

“He will play a key role in the ScotRail Alliance as we work to drive up performance for our customers and build the best railway Scotland has ever had.”