Earlier this year, NHS England, the largest employer in England, banned work flights within mainland Britain for its 1.5 million employees.
A panel was introduced in May to consider all work flight requests, and domestic air travel is only allowed in exceptional circumstances or if it saves taxpayer money.
The ban comes after it was reported by the Health Service Journal that NHS England staff had taken flights between Glasgow and London and also Manchester and London for internal meetings in 2023.
Perhaps the strongest ban has been introduced by the Environment Agency, which has not allowed staff to take domestic work flights since 2010, except in some circumstances.
The agency does not allow work flights within England and Wales, or between England and Paris, Brussels or other Eurostar destinations, for its 12,000 staff members.
It sometimes permits air travel to Scotland, but these requests are scrutinised and challenged by executive directors and must have a good business justification to be approved.