A manager at a rail firm has been criticised after telling standard class ticket-holders to stay out of the first class compartment where he was sitting.

Passenger Emma FitzPatrick posted a photograph of Mark Boon, Govia Thameslink Railway’s head of operations, on social media and said she was “totally shocked” when he told “all commuters to stay out of an empty first class carriage on a late and very packed train”.

Mr Boon was pictured with his bag on the seat next to him on the Southern service to London Victoria on Tuesday.

Hundreds of passengers replied to Ms FitzPatrick’s message, with some describing his actions as “outrageous” and “disgusting”.

One Twitter user accused Mr Boon of “rubbing salt in sore wounds”, while another suggested he “should have invited passengers into 1st Class, not fight with them”.

GTR is the parent company of the Southern, Thameslink, Great Northern and Gatwick Express brands.

A spokesman for the firm said: “Passengers need a first class ticket to travel in first class and there were other people with first class tickets in this compartment.

“This was an 11am off-peak service running just six minutes late and, while the front coaches were busy, there were seats and space in the rear coaches, as Mr Boon explained.”

Thameslink and Great Northern have suffered hundreds of delays and cancellations since new timetables were introduced on May 20.

A fault with Network Rail’s signalling system caused disruption between Gatwick Airport and Brighton on Thursday morning.

Thameslink, Southern and Gatwick Express trains are having to go more slowly on part of the route, meaning fewer services can run. Disruption was expected to continue until midday.