As someone who has been a manager involved in the removal of "perks" from employees in the past I'd like to make the following observation:
Perks are an employers method of demonstrating it's appreciation of "goodwill" from employees.
The employer reciprocates this "goodwill" by allowing easements or additions to the strict requirements of the working relationship.
The provision of these "perks" is not contractural and is subject to removal at the whim or choice or either party ....... for example, no-one is compelled to actually use staff travel concessions when flying !
I've been involved in the removal of some perks from some staff when they refused to flexibly work in a manner that was normally done but was beyond contractural requirements.
The perk was removed only for those staff who had refused to work flexibly and who made it clear they intended to continue with that approach.
They were informed that in doing so the company considered they were withdrawing their goodwill from the working relationship and so the company would not continue to allow them to benefit from the perks which were the return of that goodwill.
The employees and the union tried to claim that this action was breaking an unwritten contract and was also discrimination against those individuals.
They got nowhere on both of these claims.
It's my understanding that their legal advice was that:
"perks" are not contractural (sound familiar?)
if an individual or groups clearly act in a way which inconveniences or costs their employer then the employer is at liberty to withdraw it's goodwill (perks) from only those who have acted in such way.
It is not discrimination to continue offering perks to employees who continue to demonstrate their expression of goodwill towards the company.
In my case it was made clear to the group that the company would be prepared to return the perks, but only after a period of time when the company considered they had seen sufficient examples of goodwill being demonstrated.
To me it seems that BA have done the correct thing with staff travel, the strikers clearly have no intention/wish to give BA their "goodwill" ... the company should not (you could argue cannot!) reciprocate .....
Equally, once these staff return to work and have demonstrated their goodwill to the company then the perk gets returned.
Should they return to work but continue to "work to contract" then there would be no obligation for the company to return any perk as "goodwill" would clearly still not being demonstrated.