BA will introduce a new group boarding system on all its flights on December 12.

From then, passengers will be assigned a group numbered between one and five when they check in. The priority group; group one, will be given to First Class passengers and Gold members of the BA Executive Club. Groups four and five will be the lowest tier economy passengers, with the latter reserved for those buying the cheapest hand luggage-only fares, who will board last.

The new system raises the potential problem of passengers who had paid the lowest hand-baggage only fares having no room for their carry-on because all the space in the overhead lockers has already been filled. Bags will then have to be taken off them and put into the hold.

The new policy drew much criticism on social media, with at least one passenger criticising the airline for highlighting differences between those who pay the low and high fares. However, many point out that US carriers have used the system for some time.

BA did not answer specific questions about the potential difficulties the new system could create, but said: “This method is an evolution of our long-established boarding process and has been used by airlines around the world for a number of years, including by our partners American Airlines, Iberia and Qatar.”