Rail bosses have been told to fly to some business meetings because the trains are too expensive.
Network Rail policy has advised staff that air travel should be used “where it represents the most cost effective option compared to the relevant train fare”.
Following another year of price hikes it is becoming a policy that is being increasingly used, with staff taking some 9,212 flights, 17 by Network Rail’s executive leadership team.
The cheapest flight bought by staff costing just £19.99 from Cardiff to Anglesey – the equivalent rail fare would have been as much as £84.
Other bargain flights include a £25 trip from Southampton to Manchester, compared with an advance single rail fare for £52.
A spokesman said the policy was in place “for good reason” as they are a public body using taxpayers’ money.
He told The Times: “With 98 per cent of our business travel made by rail, trains more often than not represent the best value.”